Fire Triangle Worksheet

For combustion to take place, three things must be present:

1. Fuel - the substance that burns, e.g. wood, oil.

2. Oxygen - when a fuel is burned it is reacting with the oxygen in the air.

3. Heat - this ignites the fuel and keeps the fire burning.

This can be represented in a diagram known as the Fire Triangle:

Fire triangle

The three essential ingredients for a fire are shown in the fire triangle. If any one of these ingredients is removed the fire will go out.

Fire fighters will try to remove one side of the triangle to extinguish a fire. There are several ways to extinguish a fire. Here are some:

Sand - When sand is added to a fire it removes the oxygen.

Fire Blankets - Fire blankets can be wrapped around burning objects or people. The blanket stops oxygen getting to the flame.

Carbon dioxide (CO₂) - Carbon dioxide fire extinguishers are sprayed onto the fire to remove the oxygen.

Water - Water can be added to fires to remove the heat. Water must never be used on an electrical fire or any burning oil. Adding water to burning oil will cause the cause the fire to become fiercer. Shown below is a picture of what happens when water is added to burning oil in a chip pan (not good!):

Burning chip pan

If you ever experience a chip pan fire in your home place a damp towel over the pan, call 999 and leave the house.

Which if the following is the correct hazard symbol for a flammable substance?


A	B	C

A

B

C

Which of the following should never be added to an electrical fire?

Water

Sand

Carbon dioxide

Fire blanket

Tim is filling his petrol mower and accidentally spills some of the petrol. Which of the following should be added to to the spillage to prevent fire?

Sand

Carbon dioxide

Fire blanket

Which of the following should be found in every home (as recommended by the fire service), to protect you and your home from fire? Tick all the answers that you think are necessary.

Smoke alarm

Fire blanket

Sprinkler system

Carbon dioxide fire extinguisher

ANSWERS

Question 1

Which if the following is the correct hazard symbol for a flammable substance?


A	B	C

CORRECT ANSWER

B

EDDIE SAYS

This hazard symbol must appear on all flammable substances used in science lab.

ANSWERS

Question 2

Tick the substances below that are required for combustion to take place.

CORRECT ANSWER

Heat
Fuel
Oxygen

EDDIE SAYS

Heat, Fuel and Oxygen are the three sides of the fire triangle. Petrol is an example of a fuel, which is why "fuel" is better here. Water and CO₂ are products of the fire.

ANSWERS

Question 3

Which of the following substances can be used to extinguish a fire?

CORRECT ANSWER

Carbon dioxide
Water
Sand

EDDIE SAYS

There are many ways to put out a fire but carbon dioxide, water and sand are amongst the most common.

ANSWERS

Question 4

Which of the following should never be added to an electrical fire?

CORRECT ANSWER

Water

EDDIE SAYS

Water should never be added to an electrical fire as it will increase the risk of electric shock and may cause further fires.

ANSWERS

Question 5

Tim is filling his petrol mower and accidentally spills some of the petrol. Which of the following should be added to to the spillage to prevent fire?

CORRECT ANSWER

Sand

EDDIE SAYS

Sand would prevent oxygen getting to the fuel and will reduce the risk of it igniting. Fire blankets would be too small to cover such a spillage and the risk would still remain when the blanket is removed.

ANSWERS

ANSWERS

Question 7

Which of the following should be found in every home (as recommended by the fire service), to protect you and your home from fire? Tick all the answers that you think are necessary.

CORRECT ANSWER

Smoke alarm
Fire blanket
Carbon dioxide fire extinguisher

EDDIE SAYS

It is very important that you are aware of fire safety procedures - if you aren't, make sure you do some research to be completely sure. It could be a matter of life and death!