ISO/TR 25743:2010

TECHNICAL ISO/TR
REPORT 25743
First edition
2010-04-01

Lifts (elevators) — Study of the use of
lifts for evacuation during an emergency
Ascenseurs — Étude de l'utilisation des ascenseurs pour l'évacuation
lors d'une situation d'urgence




Reference number
ISO/TR 25743:2010(E)
©
ISO 2010

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ISO/TR 25743:2010(E)
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ISO/TR 25743:2010(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Terms and definitions .1
3 Abbreviated terms.2
4 Use of the decision chart.2
4.1 General .2
4.2 Example of use of the decision chart.3
Annex A (normative) Further explanation of technical solutions required .14
Annex B (informative) Summary of requirements .27
Annex C (informative) Lift design limitations.29
Bibliography.30

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ISO/TR 25743:2010(E)
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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
In exceptional circumstances, when a technical committee has collected data of a different kind from that
which is normally published as an International Standard (“state of the art”, for example), it may decide by a
simple majority vote of its participating members to publish a Technical Report. A Technical Report is entirely
informative in nature and does not have to be reviewed until the data it provides are considered to be no
longer valid or useful.
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.
ISO/TR 25743 was prepared by Technical Committee ISO/TC 178, Lifts, escalators and moving walks.
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ISO/TR 25743:2010(E)
Introduction
This Technical Report has been prepared in response to a request for an investigation into the implications of
1)
the use of lifts (elevators) for the evacuation of persons during various types of building emergencies. There
has been considerable debate over recent years with regards to the hazards and risk associated with using
lifts for evacuation. There is clearly a need to determine what hazards and risks exist and what can be done to
the building and lifts to minimize these risks if lifts were to be used.
The purpose of this Technical Report is to investigate the risks to persons using lifts to evacuate a building
during an emergency.
Lift engineers and firefighters were involved in the production of this Technical Report. It is fully recognized
that lift engineers are not experts in building design or fire engineering; therefore, this Technical Report does
not attempt to resolve issues in these areas. It aims to make clear to those persons involved in building design
and fire engineering the issues that need to be addressed. Not all of the issues set out in this Technical
Report need to be addressed in all building designs.
There are many reasons why a building can need to be evacuated, such as a fire, explosion, chemical or
biological attack, flooding, storm damage or earthquake. Not all of these are relevant to every building and
other possible risks are so unlikely to occur that they can be disregarded. It is the responsibility of the building
designer(s) to determine whether a particular risk is sufficiently great to require addressing.
If, for example, a small office block is being designed for a mid-town area, it is within the realms of possibility
that it can be subjected to an explosion or chemical attack (as a result of terrorism). It is not, however, very
likely to be the case unless there exists some particular reason to make it attractive or susceptible. In most
cases, the risk of these events is probably so low as to make it unnecessary for them to be addressed.
If a building is intended to be the headquarters of the military, this increases the likelihood of it being subjected
to some form of attack. It is, in that case, necessary to consider the effect of an explosion in or close to the
building or a chemical agent being introduced into the building.
A building constructed in an area where earthquakes do not normally occur need not have provisions made
for such an event.
If a building is intended to be located in the centre of a city to form a prestigious landmark, consideration of all
the possible events that might occur can be essential.
It is the responsibility of the designer of the building to determine by risk assessment or other methods what
events reasonably need to be addressed. Once this is done, the chart provided in Figure 1 can be used to see
what needs to be considered, if lifts are to play a part in any evacuation strategy.
A lift or lifts can allow disabled persons to evacuate a building in relative ease, but if it is thought that lifts can
play a role in general evacuation, it is possible for them to make a significant contribution to reducing the
general evacuation time. This depends on the building size, number of lifts, etc.
This Technical Report does not concentrate on the evacuation of disabled persons, but instead highlights and
addresses the hazards and risks to which all users can be exposed if lifts are used for evacuation.
Even if it is thought that lifts can play a part in a general evacuation, it could prove to be uneconomic. It is not
suggested that lifts should replace stairs or that using lifts instead of stairs will increase evacuation times in
many building designs.

1) Hereinafter, the term “lift” is used instead of the term “elevator”. In addition, the term “lift” is also used instead of the
terms “lifts, escalators and moving walks”.
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TECHNICAL REPORT ISO/TR 25743:2010(E)

Lifts (elevators) — Study of the use of lifts for evacuation
during an emergency
1 Scope
This Technical Report investigates and highlights the main risks associated with using lifts (elevators) for the
evacuation of persons in various types of emergency.
The types of emergency under study arise from fire, flood, earthquake, explosion, biological or chemical
attack, gas leakage, lightning or storm damage in the building being studied or a building adjacent to it.
The purpose of this Technical Report is to provide a process for making decisions relevant to the design of
lifts and buildings, in order to determine if a given design can enable the lifts involved to be used with an
acceptable level of safety.
It is not intended that all buildings be designed for all risks and, consequently, it is not intended that all lifts
incorporate all features mentioned. It is the responsibility of the building designer to determine events that are
likely to occur, given the building's importance, function, occupancy, status, location, use, size, etc.
It is not the responsibility of, nor is it possible for, lift manufacturers to determine whether or not a lift can be
used safely as a means of evacuation in a given building. It is the responsibility of other parties to make this
decision. The lift manufacturer can only advise on the capabilities of a particular lift design or the status of the
lift at a particular point in time.
The philosophy adopted in this Technical Report can be applied to any building, be it large, small, new or
existing. In practice, its application to existing building designs can prove to be difficult and uneconomic in
many instances.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
building management system
BMS
system capable of making intelligent decisions based on information sent to it
2.2
building management
persons or organization responsible for ensuring the day-to-day safe, efficient running of the building and for
ensuring that the building is safely evacuated in line with the evacuation strategy in an emergency
2.3
emergency command centre
room, area or location within or outside the building, where those responsible for evacuation receive
information, issue instructions and manage events as they unfold
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ISO/TR 25743:2010(E)
2.4
fire compartment
fire separated area
area within a building bounded by walls, floor and ceiling, constructed from fire-resistant material, such as to
provide resistance to fire for a defined period
2.5
hazardous area
floor or area in the lift well where, due to heat, smoke, gas, etc., the environment is considered dangerous to
persons
2.6
required evacuation time
time measured from start of the lift evacuation service to completion of the evacuation of a floor or number of
floors
2.7
safe area
floor of the building where it is known that heat, smoke, etc. are not present and where it is safe for people to
exit a lift car
3 Abbreviated terms
B building-related
BL building- and lift-related
BMS building management system
L lift-related
TSR technical solution required
TSRB building technical solution required
TSRL lift technical solution required
TSRBL building and lift technical solution required
ETA estimated time of arrival
4 Use of the decision chart
4.1 General
The chart in Figure 1 should be used to study a particular building design. Where reference is made to
adjacent buildings, the intention is to consider the effects of incidents in the adjacent buildings on the building
design under study.
Steps 1 to 8 of the chart contain various numbered boxes. The numbers do not run in any particular sequence
and are provided for reference only. Certain boxes contain a series of upper case letters and a number,
e.g. TSR16B. These are inserted at points where some form of design provision needs to be made. TSR
stands for “technical solution required”. The number is the reference of the technical solution and the last letter
gives an indication of who needs to address it. “B” is used to indicate that the issue is building-related. “L” is
used when the issue is lift-related and “BL” where both are involved and a joint solution is required.
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ISO/TR 25743:2010(E)
Possible technical solutions have been identified for lift-related issues and these have been further studied
using the ISO 14798 risk methodology. Where a building solution is required, this has been left to those
responsible for building design, although some pointers are given to assist in the thought process.
An explanation of each TSR is given in Annex A and a summary of the points is given in Annex B.
4.2 Example of use of the decision chart
In the decision chart, Figure 1 a), box 1, states: Emergency detection system or building management detects
problem in building A or an adjacent building B — TSR00B.
This TSR assumes that either some system has detected an emergency or the building management has
detected it. In the case of building management, it is likely that they are observing an event or have had the
situation reported to them.
TSR00B indicates that a technical solution is required to detect emergencies and B indicates this is not a lift
issue, but a building issue, to be solved by the building designer. The solution in low-risk buildings can be a
building management procedure to deal with the situation or a simple detection system. In high-risk buildings it
can be a very sophisticated detection system. It is the responsibility of the building designer to determine the
level of sophistication required to address the given building risk. There is no need for building A to have a
system which is also monitoring building B. Building B would have its own system and in the event of a fire,
staff in building A are likely to see the adjacent building being evacuated or to see the fire.
Box 178 asks “Is the emergency a fire in building A?” and references TSR41B. Building A refers to the
building design being studied, but this building can be put at risk by events in an adjacent building. In the
decision chart, an adjacent building is referred to as Building B.
TSR41B indicates that this is an issue to be addressed by building design. Some means should be provided
to enable building management to tell if the emergency is a fire in their building.
If it is assumed that the emergency is not a fire in the building being studied (building A), then one moves to
box 174: Is it some other emergency in building A? — TSR16B.
If the answer to this is yes, box 12 is next. This explains that an explosion, terrorist attack, gas, biological
attack, water, structural failure, lightning strike or storm has occurred in the building and that it is possible for it
to affect the building structure.
These emergencies are deliberately selected because their outcome covers almost all possible emergencies.
Other emergencies, while not mentioned by name, are addressed. For example, a lorry crashing into a
building can, in the worst-case scenario, result in damage to the building structure and possible structural
failure.
After box 12, comes box 28b (TSR11B). TSR11B indicates that this is another building design issue. It is the
responsibility of the designer to decide if the building is of sufficient importance to make detecting events that
affect the building structure essential. If no provision is made to monitor the structure, this decision cannot be
made by persons other than those observing the structure.
If the event is assumed to be an earthquake then box 31 is relevant; it states: Building management or
instruments detect(s) problem and, if over magnitude X, BMS instructs lifts to shut down at defined parking
locations away from potential danger area. If event over Y, shut lift down immediately — TSR14BL.
TRS14BL indicates that there are both lift and building issues to be addressed. It is the responsibility of the
building designer to determine how and where to monitor the structure.
Once a means is provided, it is the responsibility of the designer to also decide how sophisticated the lift
reaction should be to this event. If the lift system can only be sent one signal from the monitoring system to
indicate that an event has taken place, the lift is only able to make one response. This can be to stop the lift in
flight which means that there is a high probability of passengers being trapped. If a monitoring system is able
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ISO/TR 25743:2010(E)
to indicate to the lift the magnitude of the event, then other reactions are possible “at a magnitude X, take lift to
a floor and wait”, “at a magnitude Y, stop lifts” and so on.
The lift maker needs to make the lift respond in the desired manner, but it is the responsibility of the building
designer to determine for the building what amount of structural movement is an issue requiring a reaction
from the lift system.
Box 33 says: Check equipment displacement, make slow speed check run, guide alignment, etc. — TSR15L.
TSR15L indicates that these are tasks to be managed by the lift designer. Unless some reasonable degree of
self-monitoring is provided on the lift, it is dangerous to allow it to continue to operate when the building has
undergone a large shock.
The lift system should determine if it is safe to move the lift. If it is assumed that these self-checks have
concluded that the lift should not be operated in the normal manner, then box 147 says: Recover car to
closest floor or raise alarm for trapped passengers. Signals and voice information for passengers trapped in
lift car. Notify BMS and management — TSR07L.
After checks are made, box 143 asks: Can lift be used safely?
This clearly indicates the design requirements for the lift maker in terms of signal, etc. and response of the lift.
When using the chart, it is important to always work through the particular scenario from the beginning of the
chart. If this is not done, it is likely to become misleading and lead to wrong conclusions.
Annex A provides additional information for each (TSR).
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ISO/TR 25743:2010(E)
1
START
Emergency detection system or building management
A or an adjacent building
detects problem in building B.
TSR00B
174
178
Is the emergency
in building A of a Is the emergency a
No
No
fire in
different nature?
building A?
TSR16B
TSR41B
Yes
134
19
Lifts to be recalled to
Yes Should lift be kept
No a designated floor
in service?
by BMS or
TSR42B
management
Yes
7
11
12 Building management
Problem in adjacent building B causing
Explosion, terrorist or BMS
threat to building A or threat of explosion,
5
No attack, gas, biological  does not send
fire, gas, biological attack, water, structural
Should building be
attack, water,
failure, lightning strike, hurricane or evacuation signal to lift
evacuated?
structural failure ,
earthquake in building A. At this time,
system.
TSR01B
lightning strike, storm
there is only a threat to building A.
Lifts remain in normal
Lifts are safe. Building management or BMS has occurred in the
service.
building
must determine if building is to operate as Yes
normal or if evacuation is required.
6
Management or BMS has
determined that evacuation
is required.
28
8
Is evacuation required?
Should lifts be used
TSR10B
for evacuation?
TSR38B
Yes
10
Building management or BMS
should determine which floor the
fire is on and its location in
relation to lift shaft, machine
No
room and power supply.
TSR03B
9
172
Is fire located remote
Fire is in the lift or
from lift(s) (in another fire No
fire compartment
compartment)?
containing lift.
TSR02B
To Figure 1 b) To Figure 1 b)
To Figure 1 c)
To Figure 1 b)
point K
point B point A
point J

a)  Decision step 1
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ISO/TR 25743:2010(E)
From Figure 1 a)
point A
From Figure 1 e) From Figure 1 a) From Figure 1 a)
point P point K point J
14
Is smoke adjacent to or in lift
No
shaft, lift car, machine room or
landing waiting area?
TSR04B
20
Is temperature in
waiting area and lift safe
Yes for lift users?
TSR08B
15
BMS detects smoke or fire in lift car,

hoistway, common hoistway, machine

Yes
room, landing or in same fire
compartment as lift landing.
It is not safe to use the lifts for evacuation
as planned.
21
Waiting area and lift
temperatures okay and air
clear of smoke.
Lift can be used for
evacuation.
No
22
Waiting area and lift environment
to be constantly monitored by
BMS to ensure areas remain safe.
23
Is waiting area and lift still
No
safe?
26 TSR39B
Audible and visual information required
in lift and waiting area so users know
lift is being removed from service to
safe area. Inform building control of
lift shut-down. Notify of alternative
Yes
escape routes.
TSR09BL
144
16
Run evacuation service and
Lift car(s) in common hoistway removed from service away from hazard.
continue to monitor waiting
TSR05L
environment.
17
Signs required to notify users of alternative escape
routes via stairs or other lifts in safe areas. Audible
signage by lift manufacturer and other. s.
To Figure 1 d)
TSR06BL
point D

b)  Decision step 2
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ISO/TR 25743:2010(E)
From Figure 1a)
point B
28b
Does the event affect the structure
(for example earthquake, explosion, storm damage
or lightning strike)?
TSR11B
31
Building management or instruments detect(s)
problem in the structure and, if over magnitude
X, BMS instructs lifts to shut down at defined
parking locations away from potential danger
area. If event over magnitude Y, shut
lift down immediately.
TSR14BL
33
Check equipment
displacement, make slow speed
check run, guide alignment, etc.
Can lift be moved to recover to a
floor?
TSR15L
29
Yes
Is it a water problem
(flooding)?
147
TSR12B
Recover car to closest floor and raise alarm
for trapped passengers. Signals and voice
information for passengers in lift car.
.
Notify BMS and management
TSR07L
143
Can lift be used
safely?
181
Are there
No
passengers trapped
in car?
Yes
No
34
No
All checks okay, lifts ready and
available for evacuation service . Inform
building management and BMS.
Lift to stay out of
service until evacuation service
182
required. Normal full service blocked
183
Notify BMS and
30 until full inspection by engineer .
Notify BMS that no
managment that
It is a suspected gas or
passengers in car.
passengers are
biological attack
Lift removed from
trapped and need
(lift is not damaged).
service.
rescuing.
TSR13B
146
Is evacuation now
required?
To Figure 1d)
To Figure 1g) To Figure 1f)

   point C
   point E   point L

c)  Decision step 3
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ISO/TR 25743:2010(E)
From Figure 1 g) From Figure 1 h)
From Figure 1 c) From Figure 1 f)
From Figure 1 e) From Figure 1 b)
    point S
    point C    point M    point N
    point R    point D
101
Signs and audible instructions required to inform people to
evacuate building. Lifts and stairs available.
102
Are all lifts available for No
evacuation?
Yes 103
Some lifts are not available.
148
      Is it likely that passengers
will be exposed to a hazard while the lift
     is on its way to the exit floor?
TSR17B
104
Are there enough lifts to
No
assist evacuation?
TSR18BL
109 No
Notify BMS and management.
Park any lifts still in service. Turn
Yes
on signs and audible warnings to
inform people that lifts are not
available and stairs are to be used.
TSR19L
110
Should all lifts serve all floors?
TSR40B
Yes
110B
No
Shoud priority be given to
certain floors?
TSR46B
Yes
No
To Figure 1 e)
point F box
111
     112
Serve floors as instructed by BMS.
To Figure 1 e)
point H box
     113

d)  Decision step 4
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ISO/TR 25743:2010(E)
From Figure 1 d)
  point F box
From Figure 1 d)
    110B
  point H box
     111
119
Continue to clear floor
112
113
Phased evacuation. Serve specified floors (e.g. one
Turn on evacuation signs and audible
above plus one below) prior to changing to designated
warnings at all floors to be served. Turn on
floors or other routine.
NO SERVICE signs at floors not served.
TSR22BL
114
Lift called and people have to wait. Panic or concern
can arise. Lobby can become crowded.
TSR21B
150
Is waiting environment still
safe?
TSR20B
Yes
115
Lift car arrives, but not enough space
for all persons to be rescued.
Increased concerns and risk of panic.
Risk of overloading.
TSR23BL
175
Has lift left floor on way to No
exit floor?
116
Is floor being evacuated now
cleared of people?
TSR43B
No
Yes
118
Floor is cleared; move
evacuation service to
another area.
185
BMS or building
management to determine
next floor or floors to
be evacuated.
TSR44
149
To Figure 1 d)
Are all lifts still available No
 point R box
for evacuation?
    109
To Figure 1 h)
To Figure 1 b)
   point P   point G


e)  Decision step 5
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ISO/TR 25743:2010(E)
From Figure 1 c)
   point L
120
Water detected flooding
building.
184
Is flood likely to affect
building's structural stability?
TRS45B
No
162
Shut down lift at exit floor.
Yes
Inform BMS and
management.
122
Is water close to or
No
affecting lifts?
TRS24BL
121
Does building need to be
123
evacuated?
Water detected on lift
TSR25B
landings, pit, machine room,
lift shaft.
125
No
Evacuation can take place, but
as this is not a major flood
affecting the structure,
evacuation without use of lifts
would not be a high-risk issue.
It is not envisaged that the
evacuation is urgent.
138
No Are lifts to be used for
this evacuation?
139
Are lifts to be left in normal
service?
176
Park cars at next safe stop.
Notify BMS and building
management.
140
TSR26BL
To Figure 1 d)
No action required, lifts left in
  point M
service.

f)  Decision step 6
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ISO/TR 25743:2010(E)
From Figure 1 c)
   point E
152
127
Gas or biological agent can be
undetected and not reported.
   Has gas or a dangerous
biological agent been detected No This does not produce risk for
   or reported in building? lifts only users of lifts.
No action taken and lifts remain
TSR27B
in service.
129
Is it explosive gas? No
TSR28B
132
As it is not an explosive gas, it is
assumed to be a biological agent or
poisonous gas.
Running lifts can spread the
problem due to windage from lift
cars.
130
BMS or building management should suspend lift
operation at next available safe stop.
TSR29BL
133
Should lift cars remain in
service?
No
TSR47B
Yes
135
Lifts to remain in service.
136
Is building evacuation
required?
No
Yes
To Figure 1 d)

  point N
131
Lifts shut down by management or BMS.
153
Signs and audible information required informing users that
Evacuation is not required.
service is suspended.
Lifts remain in normal service.
Users need to know what to do next.
Lift confirms to management and BMS that it is shut down.

g)  Decision step 7
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ISO/TR 25743:2010(E)
154
From Figure 1 e)
Is destination floor
   point G
(exit) still safe?
TSR30B
155
Will
...