To prevent a fire, you need to know how one starts and why it grows so fast.
The fire triangle
A fire needs three things at the same time:
- Heat (a source of ignition): a spark, a hot surface, a flame, friction;
- Fuel: anything that can burn, such as paper, wood, cardboard, fabric, rubbish, flammable liquids, gas;
- Oxygen: normal air is enough.
Take away one side of the triangle and the fire goes out. This is how every extinguishing method works:
- Remove the heat: cooling with water.
- Remove the fuel: closing a gas valve or moving materials away.
- Remove the oxygen: smothering with a fire blanket or carbon dioxide.
Prevention uses the same idea. Keep heat and fuel apart.
How fire spreads
Fire moves in four ways:
- Conduction: heat travels through metal or solid material, for example along a pipe.
- Convection: hot air and smoke rise and carry fire up stairwells, lift shafts and ducts.
- Radiation: heat travels through the air and can light things that are near but not touching.
- Direct burning: flames reach other fuel.
Why smoke is the main danger
Most people who die in fires are harmed by smoke and toxic gases, not by burns. Smoke can make you confused and unconscious in a minute or two. It is hot and dark, and you cannot see the way out. A small fire can fill a corridor with smoke very quickly.
This is why you must raise the alarm and leave straight away. Never stay to finish a task.
Common causes of fires at work
- Electrical faults and misuse: overloaded sockets, damaged cables, faulty equipment, blocked ventilation on heaters or machines.
- Cooking: unattended hot oil, grease build-up, toasters, microwaves.
- Smoking and vaping materials left burning or put into a bin.
- Heating: portable heaters near paper, clothes or curtains.
- Rubbish and storage: stacks of paper, cardboard and packaging.
- Flammable liquids and gases: cleaning fluids, solvents, aerosols, LPG cylinders.
- Hot work: welding, cutting and grinding, which throw sparks.
- Arson: deliberate fires, often started in rubbish left outside.
- Lithium-ion batteries: chargers and e-bike or scooter batteries can overheat and burn fiercely, with little warning.
How buildings help slow a fire
Buildings are divided into compartments with fire-resisting walls, floors and fire doors. These keep fire and smoke in one area for a time, so people can leave. A hole in a compartment wall, or a fire door wedged open, can let fire run through the building. The next lessons explain how to keep them working.
Fire grows fast
A small fire can become a big one in minutes. Flames spread quickly over furniture, stock and packaging, and a room can reach a flashover point where everything in it ignites. This is why the first minutes matter most: raise the alarm early, and do not wait to see if a fire will go out by itself.
Key points
- Fire needs heat, fuel and oxygen. Remove one and it goes out.
- Smoke, not flame, kills most people.
- Many workplace fires start from electrical faults, cooking, rubbish, heaters, smoking and hot work.
- Compartments and fire doors give you time to escape.