By Dr. Sylvia Heilmann. The fact that humans are unpredictable creatures is also clearly demonstrated in the area of fire protection: Designers think ahead, calculate all risks and try to work out any eventualities – yet nevertheless fail to succeed on many occasions due to unpredictable human behaviour.
The user will do what they want – and they are perfectly entitled to do so. As long as they don’t do anything wrong e.g.:
- dismissing the fire protection officer,
- locking escape doors,
- covering the escape route signs,
- allowing regular training sessions on fire protection to become more like coffee breaks,
- converting storerooms into offices,
- failing to keep plans of the emergency routes up-to-date,
- letting the fire safety regulations become unreadable or
- failing to donate old hand-held fire extinguishers to the fire service museum.
Which habits need to be regimented and which are wrong but not dangerous?
Fire protection is generally effective and feasible in the long term when it does not hinder or restrict daily usage. This will then allow the intended measures to take effect in the event of a fire and thus the desired level of safety can be achieved. User habits play a decisive role here. A differentiation can be made between intended, prohibited and changeable user habits.
Intended user habits
Fire protection can become ineffective through intended usage processes or habits which, although they are typical for users, have not been taken into account in planning. The influence of organisational measures can only have an effect here to a limited extent. This is because intended usage processes must actually serve the intended purpose – meaning they are part of the use of the building – and are thus hard to influence using impractical or enforced organisation. In addition, it is not expedient to want to restrict or change indispensable usage processes or intended user habits. Therefore, user requirements must be known at the planning stage and the usage concept must form part of the planning contract. Intended user habits include e.g.:
- cloakrooms in the corridors of primary schools or nurseries (see Figure 1),
- castors on care beds in old people‘s homes,
- fire loads that are deemed necessary in required corridors in hotels (see Figure 2) or office units (see Figure 3), etc.
These mostly unchangeable user habits can result in safety deficits if they are not already considered in the fire protection concept.
Prohibited user habits
Most safety deficits that arise unnoticed result from the user of the building making changes at a later point in time. This could be e.g. setting up information stands, reception desks or seating – and thus fire loads – in the reception area or foyer that were not taken into account in the fire protection planning. These fire loads are then usually located directly next to or within emergency routes and can also restrict their width. In many cases, this affects the required exit from a stairwell that can then no longer be safely used. This situation requires analysis based on fire protection aspects and is only permitted if other emergency routes and exits to the outside are available.
Alternatively, the safety of this emergency route can be ensured using active fire protection measures e.g. a sprinkler system. It is often the case that organisational fire prevention – i.e. regularly checking the observance of safety regulations – is neglected in normal operation. Otherwise avoidable situations can thus be found again and again in practice that could result in real danger (see Figure 4).
Prohibited user habits also include:
- obstructing emergency exits (see Figure 6),
- using emergency routes as common areas e.g. with seating in required corridors (see Figure 2),
- turning emergency routes into functional areas e.g. positioning coffee and vending machines in stairwells or corridors, photocopiers or cloakrooms in required corridors or information desks in the foyer, etc. (see Figure 7),
- using unauthorised door stoppers to hold fire and smoke protection doors open (see Figure 5).
The situations in Figures 4, 6 and 7 are examples of deficiencies in organisational fire prevention. They represent a real danger and must be promptly rectified. As the organisational measures do not usually require any structural changes, a maximum time period of two weeks appears suitable for the prompt rectification of the deficiencies.
The situations in the required corridors shown in Figures 1, 2 and 3 are initially prohibited but could be resolved conceptually in the fire protection certificate (e.g. by making it unnecessary to have a required corridor by forming functional units) or by making structural modifications (e.g. the installation of an approved and reliable hold-open system instead of the door stopper in Figure 5).
Changeable usage habits or usage restrictions
A fire protection concept comprises passive, active and operational/organisational measures. Preventative fire protection does not consist of isolated single measures but a coordinated system of precautionary measures that only deliver complete protection in combination. The failure to carry out an organisational measure or a change to a utilisation process can thus mean that the safety concept becomes obsolete. In an extreme case, the changes to the utilisation parameters can result in a danger to public safety and order.
Therefore, the fire protection concept must acknowledge the appropriate use on an everyday basis. Usage restrictions are totally unsuitable as measures to achieve the required safety level. They require strict organisational monitoring guaranteed over the long term, which is sure to deteriorate due to human and time issues. Usage restrictions are thus unrealistic and also ineffective: If a building is designed for a certain use (see Figure 8) but this has to be restricted due to safety issues than this is a waste of the available resources. Therefore, the freedom to use a building as it was intended should be guaranteed by the design. A typical example of a usage restriction is placing a limit on the maximum possible number of people, which is usually because of the width of the available exits and could be avoided by providing additional emergency exits. If a usage restriction is unavoidable (see Figure 10), the user must guarantee that it is observed.
The two utilisation risks
- overlooked normal user habits (see Figures 1, 2, 3 and 9) and
- prohibited user habits (see Figures 4, 6 and 7)
play an important role in determining the safety level that can actually be achieved in a building. Therefore, it is necessary, on the one hand, to already define the important foundations for a functioning and practical fire prevention strategy in the long term at the design phase and, on the other hand, to involve users in the design work. Usage restrictions should be kept to a minimum. If they are nevertheless unavoidable, the operator must ensure they are observed and accept full liability for this being the case (see Figures 4 and 5).
Prof. Dr.-Ing. Sylvia Heilmann: Test engineer and publicly appointed and sworn expert for passive fire prevention
The article was published in FeuerTrutz International, issue 1.2018 (January 2018).
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