Fire Extinguishers: Safety Topics - June 2018 - Week 3


Monday - Fire Extinguisher Refresher

Three elements are necessary for a fire to start and stay ignited. Removing one of the elements stops the fire from burning and growing larger. These elements are:

  • Heat 
  • Fuel
  • Oxygen

Chemical Chain Reaction: When the temperature of the fire increases it causes a feedback reaction or cycle and as the fire grows it draws in more oxygen which creates more heat. This creates a fire that is more difficult to extinguish.  The chain reaction primarily creates the heat which maintains the fire.

Tuesday - Fuel and Heat

Types of Fuels:

  • SOLIDS: Wood, Coal, Wax, Paper, Grease, Cloth
  • LIQUIDS: Gasoline, Alcohol, Varnish, Paint
  • GAS/VAPORS: Propane, Methane, Butane, Hydrogen, Carbon Monoxide, H2S

Fuel Characteristics:

  • SPECIFIC GRAVITY: The weight of the fuel source compared to water.
  • VAPOR DENSITY: The weight of the fuel source compared to air.
  • EXPLOSIVE RANGE: The min and max amount of fuel needed to ignite or explode. 


  • STAGES OF COMBUSTION: (1) Flashpoint (2) Fire Point (3) Auto Ignition
  • HEAT TRANSFER: (1) Conduction (2) Convection (3) Radiation
  • HEAT SOURCES: (1) Open Flame (2) Electricity (3) Chemical reaction (4) Friction  (5) Compression 

Oxygen: Oxygen is the key component in the chemical reaction of a fire. Most fuels require a minimum of 16% oxygen to burn. Considering that our atmosphere is at 20.9% oxygen, it is very well sufficient in supporting combustion. 

Wednesday - Fire Extinguisher Classes and Agents

Fire Extinguishing Agents:

  • WATER: Water is the most common agent used to stop fired caused by wood, trash, or paper. Water will not work on fires caused by electrical equipment, combustibles, or liquids such as flammable gases, oil, or grease. Attempting to use water to treat these fires is very unsafe.
  • FOAM: Foam is primarily used for fires started by oil, gas, or other liquids. Foam typically has water as an additive. Foam has a cooling capacity but also a lower surface tension.

Thursday - Using a Fire Extinguisher

When using a fire extinguisher, remember the acronym P.A.S.S.

  • Pull
  • Aim
  • Squeeze
  • Sweep

Make sure to always protect yourself first! If you cannot safely control the fire, get out and leave it for the trained professionals. 

Friday - Fire Extinguisher Inspections

When inspecting a fire extinguisher, always remember:

  • LOCATION: Is it in the right place?
  • OBSTRUCTION: Is there anything in the way that prevents easy access to the fire extinguisher? 
  • PRESSURE GAGE: Is the pack recharged with proper pressure?
  • FULLNESS: Does it feel heavy? If not, replace it.
  • CONDITION: Is it in good condition or is it damaged?
  • LABELS: Is the fire extinguisher labeled correctly and is it clearly readable?
  • YEARLY: Inspect fire extinguishers every year to ensure they are working properly.

Tags: safety topics , injury prevention , personal home safety ,

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