Application of Portable Fire Extinguishers

Given a selection of portable extinguishers, full personal protective equipment, and a controlled instructional environment, the student will be able to demonstrate the proper techniques of inspecting, selecting, and using portable extinguishers...


• Extinguishes by cooling and penetrating

-----------------------------------

• Advantages

• Refills with water and air by user

• Water saturates material and prevents rekindle

• Has a good effective range

• Non-corrosive wetting agents or antifreeze may be added to the water only in extinguishers designed for them

• Intermittent use is possible

-----------------------------------

• Disadvantages

• Must be protected from freezing

• For Class A fires only

• Needs a compressed air source to charge

-----------------------------------

• Hazards

• Water will conduct electricity and spread fires of Class B origin

• Built-up air pressure must be released before removing fill cap

• Do not overfill as there will not be room for a sufficient volume of compressed air to operate extinguisher

• Shell can rupture from enclosed pressure

• Aqueous film forming foam or AFFF Extinguisher (Class A:B)

Notes: Point out difference of hose and nozzle from pressurized water extinguisher.

• Operation

• Check gauge

• Break wire seal

• Remove safety pin

• Hold extinguisher by carrying handle in one hand and operate lever at top of extinguisher

• Do not allow hand to block air passage on nozzle

• Use side-to-side sweeping motions across entire width of the fire

• Flow on top of liquids to form blanket

• Cover as much area as possible

-----------------------------------

• Advantages

• Good for use on Class A:B fires

• Acts as a foam blanket on burning liquids and is most effective on static pools of flammable liquids

• Excellent wetting and penetration properties

• Concentrations of 3% or 6% by volume with either fresh or salt water

• Fast spreading and leveling characteristics

-----------------------------------

• Disadvantages

• Effective range of only 20 feet

• Must be protected from freezing temperatures

-----------------------------------

• Hazards: stored pressure unit

-----------------------------------

• Halon portable extinguisher (Class B:C fires)

• Operation

• Similar to either stored pressure extinguisher or pressurized water type

• Discharge at base of flame

• Operate the liquid gas extinguisher the same as CO 2

-----------------------------------

• Advantages

• Halons are either gases or liquids which rapidly vaporize in fire. They leave little corrosive or abrasive residue after use

• Nonconductors of electricity

• Have compact storage container

• Visibility after use very good

• Halon is 22 times more effective than CO2

• For use on Class B or C fires; has a low Class A rating (IA-4A) in extinguishers greater than 9 lbs.

• Extinguishes by an inhibition of the combustion reaction

-----------------------------------

• Disadvantages and hazards

• Avoid breathing in confined area

• Will corrode aluminum or aluminum alloys

• Certain types of halon extinguishers may cause frostbite

-----------------------------------

• Carbon dioxide (CO2) portable extinguishers (Class B:C)

Notes: Carbon dioxide and cartridge-type extinguishers do not have gauges, but are checked by weight through routine inspection.

• Operation

• Break the wire seal

• Remove the safety pin

• Hold the extinguishers by carrying handle using one hand

• Place the thumb and the palm of the same hand on shutoff lever

• With the other hand, direct the horn

• Hold the horn by rubber or the wooden handle since it builds up a static electricity charge

• Squeeze the shutoff lever

• Direct at the base of the flame

-----------------------------------

• Advantages

• Extinguishes by smothering

• Use on Class A, B, and C fires (minimal effect on Class A)

-----------------------------------

• Disadvantages

• Poor range

Notes: Use gloves.

• Not to be stored in high temperatures

-----------------------------------

• Hazards

Notes: Place unit on ground while discharging to prevent static electricity.

• May cause frostbite

• May build up static electricity

• Shell and frosted horn conduct electricity