Fire Extinguisher In Class Training

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• Time

• Breaks

• Respect

• Questions

Purpose

• To learn about Fire Extinguishers, their uses and types.

• To learn about Fire, what fire is made up of, types and how extinguishment works.

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The Fire Triangle

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The Fire Triangle - Fuel

• Can be any combustible material, solid, liquid, or gas. All fuels must be in the form of gases in order to ignite.

• Solids: Go through PYROLYSIS where the solid is heated to the point that it releases fuel gases.

• Liquids: Go through VAPORIZATION where the liquid turns to gases through heating.

• Gases: Are already gaseous and are thus more dangerous as they are already in a condition needed for ignition.

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The Fire Triangle - Oxygen

• Under normal circumstances air contains ~21% oxygen.

• Combustion can be supported at levels as low as 14% oxygen.

• Oxygen alone is not combustible.

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The Fire Triangle - Heat

• Provides energy for the fire, causes pyrolysis and vaporization of solid and liquid fuels.

• Causes: Ignition, Continuous Production of Fuel Gases, Combustion, Rapid Spread of Fire.

• Types: Chemical, Nuclear,Mechanical, Electricity

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Fire Tetrahedron

Self-Sustaining Chemical Reaction

• The fourth Component of the Tetrahedron.• It is a result of the triangle combining to form

a chemical reaction.• It is responsible for the spread of fire.• Fires can be Extinguished by removing 1 of

the three components.

Fire Development - Stages

• Incipient Stage: Ignition, Fire is Small, Generally Confined to the Initial Ignition Material.

• Growth Stage: Smoke and Fire begin to rise, Deadly Fire Gases begin to fill the room, Thermal Layering occurs, Even at This Stage Temperatures can be Extremely High.

• Flashover Stage: Point at which fire goes from Growth to Fully Developed, When all combustibles in an area simultaneously ignite, Temps can reach upwards of 500-650C.

Fire Development - Stages

• Fully Developed Stage: All contents of the area are involved in the fire, Maximum heat is being released, Ventilation will affect the fire by pushing gases into adjacent spaces these gases will ignite as they travel into other spaces.

• Decay Stage: The heat release rate begins to decline as the fire consumes the fuel, High temps will continue due to embers. Backdrafts are very possible at this time.

Classes of Fire and Extinguishers

• Classes: A, B, C, D, K• They are represented by different colours and

symbols.• Each type has specific types of extinguishers that are

more effective than others.• Selecting the wrong extinguisher for the wrong fire

could result in spreading the fire or bodily harm.• No single Fire Extinguisher will work on all 5 types.

Class A Fires and Extinguishers: Ordinary Combustibles

• Fires include fuels such as: wood, paper, plastic, rubber, and cloth.

• Extinguisher symbol: Green Triangle with A in the middle.

Class B Fires and Extinguishers: Flammable Liquids

• Fires include fuels such as: hydrocarbon and alcohol based liquids and gases that will support combustion.

• Extinguisher symbol: Red Square with a B in the middle.

Class C Fires and Extinguishers: Electrical Equipment

• Fires include fuels such as: all fires involving energized equipment.

• Extinguisher symbol: Blue Circle with a C in the middle.

Class D Fires and Extinguishers: Combustible Metals

• Fires include fuels such as: magnesium, potassium, titanium and zirconium.

• Extinguisher symbol: Yellow Star with a D in the middle.

Class K Fires and Extinguishers: Kitchen Fires

• Fires include fuels such as: unsaturated cooking oils in deep fryers.

• Extinguisher symbol: Purple or Black Hexagon with a K in the middle.

Extinguishing Fires – Class A

• CLASS A- Extinguish ordinary combustibles by cooling the material below its ignition temperature and soaking the fibers to prevent re-ignition.

• Use pressurized water, foam or multi-purpose (ABC rated) dry chemical extinguisher. DO NOT USE carbon dioxide or ordinary (BC-rated) dry chemical extinguisher on Class A fires.

Extinguishing Fires – Class B

• CLASS B: Extinguish flammable liquids, greases by removing the oxygen, preventing the vapors from reaching the ignition source or inhibiting the chemical chain reaction.

• Foam, carbon dioxide, ordinary (BC-rated) dry chemical, multi-purpose dry chemical, and halon extinguishers may be used to fight Class B fires.

Extinguishing Fires – Class C

• CLASS C – Extinguish energized electrical equipment by using an extinguishing agent that is not capable of conducting electrical current.

• Carbon dioxide, ordinary (BC-rated) dry chemical, multi-purpose dry chemical and halon* fire extinguishers may be used to fight Class C fires.

• Do Not Use Water Extinguishers on Class C!

Extinguishing Fires – Class D

• CLASS D: Extinguish combustible metals such as magnesium, titanium, potassium and sodium with dry powder extinguishing agents specially designated for the material involved.

• In most cases, they absorb the heat from the material, cooling it below its ignition temperature.

Extinguishing Fires – Class K

• CLASS K: Designed to coat and penetrate deeply into cooking oils to smother fire from oxygen and reduce heat .

• In most cases, they absorb the heat from the material, cooling it below its ignition temperature.

How to Identify the Proper Extinguisher

• All ratings are showed on the extinguisher faceplate. Some extinguishers are marked with multiple ratings such as AB, BC and ABC. These extinguishers are capable of putting out more than one class of fire.

• Class A and B extinguishers carry a numerical rating that indicates how large a fire an experienced person can safely put out with that extinguisher.

How to Identify the Proper Extinguisher

• Class C extinguishers have only a letter rating to indicate that the extinguishing agent will not conduct electrical current. Class C extinguisher must also carry a B rating.

• Class D extinguishers carry only a letter rating indicating their effectiveness on certain amounts of specific metals.

How to Use a Potable Fire Extinguisher

• Always pull the fire alarm or ask someone to do so prior to using a fire extinguisher to put out a fire.

• “P”ull the Pin.• “A”im nozzle at the base of the Fire.• “S”queeze trigger while holding extinguisher upright.• “S”weep the extinguisher from side to side covering

the whole fire. This needs to be done not too fast or too slow.

• Always use the entire contents of the extinguisher when putting out a fire.

When not to Fight a Fire!

• If the fire is beyond the insipient stage. i.e. it has spread to other fuels.

• If you can’t fight the fire with your back to an exit.

• If the fire can block your only escape.• If you don’t have the right type or size of

equipment required to put out the fire.

When to Stop Fighting a Fire!

• If your path of escape becomes threatened.• If the extinguisher runs out.• If the extinguisher is ineffective.• If the extinguisher malfunctions.• If you feel the situation has become unsafe.• If these occur leave the area immediately

closing the door behind you.

Where to find Extinguishers on Campus

• In the corridors of academic and office buildings, and inside very large rooms.

• In or immediately outside all laboratories where chemicals are stored and used.

• In or immediately outside mechanical spaces where motorized or other equipment is present which might reasonably cause a fire.

• In campus storage buildings, and mounted inside certain university vehicles.

Questions

• Remember that this session is only half of the training you still must attend the hands on session in order to complete the training.

• Thank you for attending!