Types of Fire Extinguishers are listed below
- Water and Foam extinguishers
- Carbon Dioxide extinguishers
- Dry Chemical extinguishers
- Wet Chemical extinguishers
- Clean Agent extinguishers
- Dry Powder extinguishers
- Water Mist extinguishers
- Cartridge-Operated Dry Chemical extinguishers
- Using a Fire Extinguisher
- PASS Method
- Fire Extinguisher Inspection
- Fire Extinguisher Maintenance
Water and Foam extinguishers
Water and Foam fire extinguishers extinguish the fire by taking away the heat element of the fire triangle.
Foam agents also separate the oxygen element from the other elements.
Water extinguishers are for Class A fires only - they should not be used on Class B or C fires.
The discharge stream could spread the flammable liquid in a Class B fire or could create a shock hazard on a Class C fire.
Carbon Dioxide extinguishers
Carbon Dioxide fire extinguishers extinguish fire by taking away the oxygen element of the fire triangle and also be removing the heat with a very cold discharge.
Carbon dioxide can be used on Class B & C fires. They are usually ineffective on Class A fires.
Dry Chemical extinguishers
Dry Chemical fire extinguishers extinguish the fire primarily by interrupting the chemical reaction of the fire triangle.
Today's most widely used type of fire extinguisher is the multipurpose dry chemical that is effective on Class A, B, and C fires. This agent also works by creating a barrier between the oxygen element and the fuel element on Class A fires.
Ordinary dry chemical is for Class B & C fires only. It is important to use the correct extinguisher for the type of fuel! Using the incorrect agent can allow the fire to re-ignite after apparently being extinguished successfully.
Wet Chemical extinguishers
Wet Chemical is a new agent that extinguishes the fire by removing the heat of the fire triangle and prevents re-ignition by creating a barrier between the oxygen and fuel elements.
Wet chemical of Class K extinguishers were developed for modern, high efficiency deep fat fryers in commercial cooking operations. Some may also be used on Class A fires in commercial kitchens.
Clean Agent extinguishers
Halogenated or Clean Agent extinguishers include the halon agents as well as the newer and less ozone depleting halocarbon agents. They extinguish the fire by interrupting the chemical reaction and/or removing heat from the fire triangle.
Clean agent extinguishers are effective on Class A, B and C fires. Smaller sized handheld extinguishers are not large enough to obtain a 1A rating and may carry only a Class B and C rating.
Dry Powder extinguishers
Dry Powder extinguishers are similar to dry chemical except that they extinguish the fire by separating the fuel from the oxygen element or by removing the heat element of the fire triangle.
Types of Powder
1. ABC rated or multi-purpose powder, which contain ammonium phosphate
2. BC rated extinguishers, containing potassium bicarbonate or sodium bicarbonate, Monnex (potassium bicarbonate – urea complex). The pressurizing gas is usually nitrogen
3. A and D rated graphite powder fire extinguishers are usually used only in Class D fires
Water Mist extinguishers
Water Mist extinguishers are a recent development that extinguish the fire by taking away the heat element of the fire triangle.
They are an alternative to the clean agent extinguishers where contamination is a concern.
Water mist extinguishers are primarily for Class A fires, although they are safe for use on Class C fires as well.
Cartridge-Operated Dry Chemical extinguishers
Cartridge Operated Dry Chemical fire extinguishers extinguish the fire primarily by interrupting the chemical reaction of the fire triangle.
Like the stored pressure dry chemical extinguishers, the multipurpose dry chemical is effective on Class A, B, and C fires.
This agent also works by creating a barrier between the oxygen element and the fuel element on Class A fires.
Ordinary dry chemical is for Class B & C fires only. It is important to use the correct extinguisher for the type of fuel Using the incorrect agent can allow the fire to re-ignite after apparently being extinguished successfully.
Fire Extinguishing
Smothering
It means cutting off the supply of Oxygen in the fire.
It is done by using sand, foam, etc., to cover fire.
For extinguishing fire, carbon dioxide can be used as a Smothering agent.
Starvation
Removing of Fuel called "Starvation"
Any combustible material can be removed or gas or fuel flows shut off.
Cooling
The most commonly used fire fighting medium is water.
Water, referring to the triangle of fire, cools the heat being produced in the fire to below ignition temperature.
Using a Fire Extinguisher
The following steps should be followed when responding to incipient stage fire:
- Sound the fire alarm and call the fire department, if appropriate.
- Identify a safe evacuation path before approaching the fire. Do not allow the fire, heat, or smoke to come between you and your evacuation path.
- Select the appropriate type of fire extinguisher.
- Discharge the extinguisher within its effective range using the P.A.S.S. technique (pull, aim, squeeze, sweep).
- Back away from an extinguished fire in case it flames up again.
- Evacuate immediately if the extinguisher is empty and the fire is not out.
- Evacuate immediately if the fire progresses beyond the incipient stage.
PASS Method
Most fire extinguishers operate using the following P.A.S.S. technique:
PULL
Pull the pin. This will also break the tamper seal.
AIM
Aim low, pointing the extinguisher nozzle (or its horn or hose) at the base of the fire.
NOTE: Do not touch the plastic discharge horn on CO2 extinguishers, it gets very cold and may damage skin.
SQUEEZE
Squeeze the handle to release the extinguishing agent.
SWEEP
Sweep from side to side at the base of the fire until it appears to be out. Watch the area. If the fire re-ignites, repeat steps 2 - 4.
Fire Extinguisher Inspection
Like any mechanical device, fire extinguishers must be maintained on a regular basis to ensure their proper operation.
You, the owner or occupant of the property where the fire extinguishers are located, are responsible for arranging your fire extinguishers' maintenance.
Fire extinguishers must be inspected or given a "quick check" every 30 days.
For most extinguishers, this is a job that you can easily do by locating the extinguishers in your workplace and answering the three questions below.
- Is the extinguisher in the correct location?
- Is it visible and accessible?
- Does the gauge or pressure indicator show the correct pressure?