Building fire safety
In the recent past, there have been several building fire accidents in Malawi. The most notable of these accidents have been in Blantyre. Towards the end of last year in October, another fire razed the Escom building downtown in Blantyre. Then, earlier this year, in March alone, there have been two building fire accidents involving the Farmers Organisation warehouse in Chitawira and Keza Office Park at Chichiri.
Against this background, this article seeks to enlighten the general public on the basics of fire safety in buildings.
A fire is the culmination of a chemical reaction called combustion which involves a fuel and oxygen to produce flames and smoke. This chemical reaction progresses in four stages namely; ignition, growth, stable growth and finally, decay. In order for a fire to start, there must be three necessary conditions also known as the triangle of fire: heat, fuel and oxygen.
Fire accidents in buildings can be caused by a wide range of factors including natural phenomenon such as lighting, human carelessness, technological failure and arson.
It is very important to ensure safety against building fires. The issue of safety can be dealt with from different perspectives and levels in the development of the fire including prevention, escape, containment and extinguishment.
The first line of defence in dealing with fire risks is prevention. All the necessary measures must be taken to prevent the occurrence of a fire outbreak. Attempts have to be made at limiting the availability of either the fuel, heat or oxygen supplies. This can be achieved through, amongst others, careful selection of building materials. Most widely used building materials provide ready supplies of fuel for building fires. However, depending on chemical composition, certain materials are more likely to burn than others.
Generally, it is safer to use materials having lower potentials of ignitability —the material’s ease with which it can be ignited when exposed to a flame, combustibility—the material’s likelihood to burn when subjected to heat from an existing fire, fire propagation—the material’s contribution to the spread of fire through its own heat output when it is heated, surface flame spread –the material’s support for the spread of flames across its surfaces, smoke obscuration–the material’s production of smoke when burning and finally, higher fire resistance – the material’s retention of its load bearing capacity and insulating properties when exposed to fire.
Safer material finishes include brickwork, concrete, ceramic tiles, glass and plasters. Materials to treat with extreme caution include timber and its associated products, plastics and decorative laminates.
It is also very important to consider the fire and smoke ratings of furniture and upholstery items.
Real life situations can hardly ever be accurately planned for. Thus in terms of building fires, prevention alone cannot provide guarantee of safety. In the event that a fire has broken out in a building, the safe evacuation of the occupants becomes the thin line between life and death. The buildings must be provided with multiple sufficiently sized escape routes strategically positioned within the building space. These routes must always remain clear of obstructions and be fitted with clear signage and lighting.
The speed at which the fire spreads from the origin to other parts of the building is another key factor to consider for safety. A fire that rapidly spreads through the building space significantly lowers the chance of a safe evacuation from the building. It is, therefore, important to ensure that the various space delineating elements within the building are capable of containing the fire within the same place for reasonably longer periods of time. One way of enhancing fire containment would be to use building elements that are thicker and having a higher fire resistance. Thicker elements serve to attenuate the passage of heat from the originating space to other adjoining spaces.
Extinguishment is the very final stage in dealing with a building fire outbreak. Buildings may be fitted with portable fire extinguishing tools such as carbon dioxide cylinders and fire hose reels. These tools must be regularly serviced and strategically positioned for efficiency.
In this modern age of automation, some technological innovations can significantly increase the efficiency in dealing with building fires. The market is awash with a range of devices which can detect fires and smoke using infrared technology. These devices can then trigger the necessary response such as raising a fire alarm and or an automatic fire extinguishment procedure.
Building fire safety ought to be a collective responsibility. The building designers must ensure the adequate fire safety provisions and users be responsible aswell. The authorities must ensure the enforcement of minimum building fire safety standards and fire brigade must modernise and improve their efficiency at handling fire accidents.
