Fire comes from a chemical reaction between oxygen (usually from the air) and a fuel (e.g., wood or petrol). For the reaction (combustion) to occur the fuel must be heated to its ignition temperature.
Once the combustion process is underway it is self-perpetuating. The heat of the flame itself keeps the fuel at the ignition temperature, so it continues to burn if there is fuel and oxygen around it.
For a fire to start the three components of fuel, oxygen, and heat must be present. To put out a fire one of the three components must be removed. This is often presented as a ‘fire triangle’.
Fire safety is managed through a process of risk assessment and management. A fire safety management system will typically have three lines of defence:
Fire prevention measures look to eliminate, reduce, or effectively manage sources of fuel, heat and oxygen:
| Fuel | Combustible fixtures fittings and stored goods Highly flammable or explosive substances e.g., LPG |
| Heat | Hot work Friction from mechanical parts Exothermic chemical reactions Lighting Electrical equipment Smokers materials Arson |
| Oxygen | Oxidising chemicals Oxygen in cylinders |
Buildings are constructed of fire-resistant materials and designed with structural compartments which control the spread of fire and smoke and protected escape routes to enable safe escape.
Systems can also be installed to automatically detect fire and raise the alarm so that people can escape and/or automatically suppress the fire (e.g., sprinkler systems) to protect the building structure.
Portable fire-fighting equipment is specified according to likely fuel sources and scale of the fire.
The primary objective of emergency evacuation is to ensure that in the event of a fire, the occupants of a building can reach a place of ultimate safety outside the building. The best way to evaluate the effectiveness of the emergency plan is to perform a fire drill. Every member of staff should participate in a fire drill at least annually.