Buildings escaping fires

Since the introduction of the Fire Services Act of 1947, the fire authorities have had the responsibility for fighting fires in all types of premises. In 1971, the Fire Precautions Act gave the fire authorities control over certain fire procedures, means of escape and basic fire protection equipment through the drawing up and issuing of Fire Certificates in certain categories of building. The Fire Certification was mainly introduced to combat a number of serious industrial fires that had occurred. 

NFPA 80 identifies fire doors as closures placed at given points in a building to compartmentalize, or contain, fire and smoke in the area of origination to prevent it from spreading. They also serve to protect the path of egress, or escape. Fire doors consist of assemblies that include handles, seals, closer assemblies, door frames, and... 

The building should be designed so that any compart-mentation affords the occupants sufficient time to escape from the compartment of origin before being overcome by fire and smoke. However, it is difficult to calculate precise times because people, buildings and fires vary, and most codes and legislation specify distances based on experience of past fires and past experiences. 

In order to ensure the safe evacuation of people in the event of fire it is not possible merely to rely on building design, adequate means of escape, fire alarms, emergency lighting, etc. In all but the smallest workplaces it will be necessary to have staff that have been trained to assist with emergency evacuation. Specifically those people responsible for fire safety within buildings and outside venues will need to consider the provision of fire wardens/marshals, crowd safety stewards, fire alarm verifiers and fire incident controllers. 

The specific technical requirements within each category will depend upon the type of building and the use to which it will be put. For example, the requirements for fire escapes will be different for an office and for a factory. 

A whole range of precautions may be based on the principles summarized earlier. However, general precautions, applicable to the majority of work situations, are listed in Table 5.13, many of which are included in legal requirements. For example, in the UK The Fire Precautions Act 1971 specifies requirements for fire resistance of surfaces and building structure, assessment of risk, means of escape, means for giving warning, firefighting equipment, and fire instruction and drills. 

The calculation of the fire s outcome in the third step includes the distribution of heat, smoke, and toxic gases throughout the building of concern. It allows the introduction of people into that building and monitors their movement in response to the fire. They may escape safely or fail to escape due to heat or the inhalation of toxic smoke. The benefits of changing some component of the defined fire problem is observed in the change in the number of deaths predicted, rather than by direct comparison of the toxic potencies of the different smokes. This mirrors the complexity of real-life fires. 

A Fire Hazard Index. There are a number of situations where all that is needed is an indication of whether a change in a specific commercial product is beneficial or not. In these cases, one can presume that the people exposed to the fire and the building in which the fire exists are fixed. Moreover, it must be established that toxicity is the sole threat to escape, not smoke obscuration or heat. 

Note that this index only produces a relative number. Two products with widely different values of the index might be equally safe if, in fact, neither impedes escape. Conversely, two products with apparently similar values may produce different hazard levels if both products are close to the margin of safety. Thus, the scale for any index must be "calibrated", and it may well be different for each building or type of occupant. Generally, this will require a more complete hazard analysis and/or full-scale fire tests. Protocols for doing this are currently under consideration. 

Process fires are very similar whether they occur outside or in enclosed buildings. The major differences are that products of combustion (toxic fumes, smoke, CO, CO2) build-up in an enclosure very quickly and can incapacitate personnel and hinder escape. Depending on the location and size of the fire, personnel will not have much time (less than one minute) to escape the building. It is important that life safety issues be handled by foil owing the applicable building code and NFPA 101, Fife Safety Code. 

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