Philadelphia Fire Department's KidZone!

Course #5: Sizzling Science


Chemistry of Fire


Fuel is anything that will burn.
Heat is anything that gets hot enough to make fuel burn.
Oxygen is one of the gases in the air around us.

Firefighters look at these as a triangle. You must have all 3 sides to complete the shape, and you must have all 3 elements to make a fire.

Removing Heat

You can remove heat from a fire by using water to cool it down. When a firefighter uses water to put out a flame, it lowers the temperature of the fire to a point where it will no longer burn.

Removing Oxygen

You can remove oxygen from a small fire by covering it with a blanket, dirt or sand. These things stop the fire from getting enough oxygen, and the fire will smother and go out.

If your clothes catch on fire, you can also remove oxygen by smothering the flames against the floor. Remember: STOP, DROP, COVER, and ROCK!

Removing Fuel

You can remove fuel from a fire by removing unburned fuel. Forest firefighters will remove trees in the path of the fire, so when the fire reaches that point there is nothing to burn. If the fire has no fuel, it will go out!

Keep your room clear of clutter, and fires will have less to burn and less chance to spread.

Smoke can Kill You!

The smoke created by fire contain poisonous gases. Sometimes only a few breaths of smoke can be really harmful, and possibly kill you. 30% of all fire deaths are due to smoke inhalation!

You must plan a quick escape route in order to escape from smoke and fire!

Smoke and Heat Rise

Smoke and heat are lighter than air, so they rise. The greatest amount of smoke and heat is found toward the ceiling. The coolest and freshest air is found near the floor.

So crawl on your hands and knees when traveling through smoke. Cover your mouth with a cloth and take short breaths.