How do Fires Start?
Last updated:- Faulty electrics are a very common cause of workplace fires:
- Storing flammable or combustible materials or substances close to a heat source;
- Human Error - tends to be the result of sloppy or careless behaviour, or not following correct procedures.
- Arson where buildings are unprotected and prone to vandalism. Refuse bins should ideally be 8m away from the building and secured to an anchor point to prevent them being rolled under an overhang and set on fire.
4.1 How Fires are Put Out
There are three basic ways of extinguishing a fire i.e. breaking the Fire Triangle these can be used singly or in any combination. They are:
4.2 Starvation
Fires need fuel, if the fire can be starved of fuel it will die out. This can be achieved by:
- taking the fuel away from the fire, e.g. turning off the gas supply to a gas fire
- taking the fire away from the fuel e.g. removing the burning section away from the fuel source;
- reducing the quantity of fuel e.g. a bonfire out in the open that isn’t in contact with any other wood or dry grass will burn itself out
4.3 Smothering
Fires need oxygen and the supply of oxygen to the fire can be controlled by:
- covering the fire in a layer of material which prevents oxygen getting in e.g. sand or a fire blanket
- reducing the amount of oxygen around the fire by replacing it with a gas that will not allow flames to burn e.g. carbon dioxide
4.4 Cooling
Fires need a source of ignition, in other words a source of heat, which is sufficient to raise the fuel to a temperature at which it will burn.
- Once a fire is established some of the heat of combustion is returned to the fuel to provide a source of ignition.
- If heat can be taken out of the fire then it will lose this ignition source. The most common and cheapest way of cooling a fire is to pour water on it. The heat of the fire is then used up in boiling the water until there is insufficient heat available to ignite the fuel.