An Introduction to “Fire Extinguishers”

Crusoe 7-10 Secondary CollegeScience

Senior Green Team

OBJECTIVES:After this training you should be able to:

• IDENTIFY 3 common classes of fires • SELECT the proper type of extinguisher • EVALUATE when it is safe to fight an “early-stage” fire, and; • APPLY the “P.A.S.S. method to operate a portable extinguisher.

UNTRAINED PEOPLE Cannot use a fire extinguisher safely

because they are:

• UNABLE to evaluate a fire

• UNAWARE of DANGER due to...

• LACKING JUDGEMENT regarding:– Safe and correct use of, and – Limitations of portable extinguishers

WHY UNTRAINED PEOPLECan’t use a fire extinguisher safely

(continued):

INEXPERIENCED• Don’t know about the

proper type of extinguisher • Don’t know how to make

a “Fight or Flight” analysis• Unfamiliar with the

“P.A.S.S. method”

COMMON FIRE CLASSIFICATIONS

“Ordinary” combustibles Paper, wood, rubber, plastics

and textiles.

“Flammable liquids” Oil, gasoline, solvents

“Energized circuits”

Electrical equipment and computers

E

HOW THEY WORK:

• Works by cooling. • Numerical rating indicates amount of agent,

duration, and range of discharge on test fires.• Area of Class A fire which a “non-expert” can

extinguish, with proper training – 1-A is equivalent on Class-A fire to five liters of water. – 2-A contains has twice as much extinguishing agent.

HOW THEY WORK:

• Works by blanketing the fuel. • Interrupts chemical reaction at fuel surface.

HOW THEY WORK:

• Class “E” units have no numerical rating.• A Class “E” rating doesn’t imply any capacity.• Only indicates that the extinguishing agent is

non-conductive, safe on energized equipment.• Works by displacing oxygen, smothering fire.

E

Portable Fire Extinguishers• Can be CARRIED to a fire• Weigh from 1.5 to 20 kg

Portable Fire Extinguishers

LIMITED IN:• Capacity - 1.5 to 9 kg. of

extinguishing agent

• Range - Typically 1 to 3 m

• Duration - Discharge their contents in only 5 to 30 seconds!

Extinguisher Common features

• Locking pin• Carrying handle / operating lever • Pressure gauge• Label :

– Type (Water, C02, Dry Chemical)– Classification (A, B, C)– Instructions

• Discharge nozzle or horn

COMMON TYPES OF FIRE EXTINGUISHERS:

• WATER • DRY CHEMICAL• CO2

WATER• Water + CO2 propellant• ONLY for Class fires

–wood / paper, etc.• Spreads burning liquids!• DANGER of electric shock

if used on on live circuits!

DRY CHEMICAL MULTI-PURPOSE RATED

• Best for general use:• Reduced risk of re-ignition• A 3.5kg. unit empties in 8-10 secs.

– Effective range of 2 ft. to 5 m.

Either Or

C02 - Rated• Best on burning liquids / electrical• SHORT range - 1 to 3 m.• 6- kg unit empties in 5 to 10 seconds!

– Use short spurts!• DISPERSES QUICKLY!

– Continue applying after the fire is out!• Unit gets VERY cold - hold properly

In case of burning odor or smoke:

• Call 911 First!• Notify Security - X 43434• Disconnect Equipment

– Remove combustibles, if you can do so without danger to yourself

• Notify Floor Monitors– and Emergency Safety Coordinator

REACT upon discovery of fire or smoke

Remove persons in immediate danger!Ensure doors are closed! (confine fire/smoke)

Activate the building alarm !Call the Fire Department !Treat ALL fires as DANGEROUS!

– Continue a complete building evacuation– Do not attempt to fight a fire UNLESS you are

OSHA certified in use of a fire extinguisher !

Use a portable extinguisher ONLY if the:

• Building is being evacuated (Fire alarm has been pulled)• Fire Department has been called (Dial 911!)• Fire is NOT spreading (small and contained)• EXIT IS CLEAR (fight fire with your back to an exit ) • Proper extinguisher is at hand, and...

– You have been trained and know how to use it!– You use “Buddy System” - have someone back you up!

• Get assistance BEFORE trying to fight a fire!

Remember the PASS word:

1) Keep your back to a clear escape route,

2) Stand back 2 to 3 feet from the fire,

3) Then >>:

P.A.S.S.PULL

AIM

SQUEEZE

SWEEP

PULL the pin

AIMLOW at the base of the fire

SQUEEZEthe lever

SWEEPfrom side to side

OK, It’s out…Now What?• WATCH the fire area

– If the fire flares up again repeat! – If you can’t control the fire, LEAVE immediately!

• Call the fire department to inspect the scene! • Recharge or replace any used fire extinguisher!