Fire Extinguishers

Team 6Garrett Ellanson

Jeffrey EthierSean Tacey

Inspection

• OSHA requires that fire extinguishers be inspected annually and must keep records of this inspection for a year.

• When fire extinguishers are being inspected or recharged, a suitable replacement device must be present until the fire extinguisher is returned.

Using a Fire Extinguisher

• If a fire is to occur in the laboratory, or elsewhere, one should remember the acronym P.A.S.S.:

1) Pull2) Aim3) Squeeze 4) Sweep

Pull the Pin

• This step involves pulling the pin to prime the fire extinguisher for use.

Aim at the Base of the Fire

• This step is important! If one were to aim at the top of flames, the fuel source will not be extinguished when the fire extinguisher is used.

Squeeze the Handle

• Performing this action releases the extinguishing agent from the fire extinguisher.

Sweep From Side to Side

• This step ensures that the entire fire is extinguished as the extinguisher is used.

Location of Fire Extinguishers in the Lab

The enclosed red circles represent fire extinguishers.

The Fire Triangle

• For a fire to be sustainable, it needs

1. Enough Oxygen to sustain combustion.

2. Enough Heat to remain at the combustion temperature.

3. Fuel to provide a source for the combustion.

• If any of the above three items are removed from a fire, it will be extinguished.

Classes of FiresClass Description Example

A Fires that involve ordinary combustible materials

Cloth, wood, and paper

B Involve flammable and combustible liquids

Gasoline and alcohol

C Involve electrical fires Outlet fire

D Fires caused by combustible metals

Magnesium, titanium, and sodium

K For use in “kitchen/cooking fires”

Vegetable oil, animal oils, and fats

Labels on Fire Extinguishers

• Before using a fire extinguisher it is important to know the source that is causing the fire (which class of fire is occurring).

• Also, it is important to know what type of fire extinguisher is used for each class.

• The fire extinguishers in our laboratory are designed to handle Class A, B, and C fires.

Different Types of Propellant Storage

• Stored Pressure– The propellant is stored with the flame

extinguishing agents• Cartridge– Requires a separate cartridge to be inserted for

propellant.

Variety is the spice of life

• Different fires require different extinguishing agents– Though there is no standard for color,

extinguishers are labeled with pictograms• Most common color-contents:– Yellow used for Combustible Metals extinguisher– Silver/White contains Water– In United States, most extinguishers are Red

Different Types of Extinguishers

• Typically, one will encounter three types of fire extinguishers:

1. Pressurized water models2. Carbon dioxide (CO2) extinguishers

3. Dry-chemical extinguishers4. Sodium bicarbonate extinguishers5. Potassium bicarbonate extinguishers6. Foam extinguishers (AEFF and FFFP)

Pressurized Water Models

• Typically silver and are about 2 feet tall and 25 pounds in weight.

• Filled with tap water and pressurized air

• Are meant for Class A fires.

Carbon Dioxide Extinguishers

• These extinguishers are usually red and vary in size.

• On larger models there will usually be a horn attached to aim the extinguisher.

• Designed for Class B and C fires.

Dry Chemical Extinguishers

• Are red in color and vary in size (typically from about 5 to 20 lbs).

• They contain a yellow powder that consists of monoammonium phosphate and are pressurized with nitrogen.

• Are used for either A,B, and C fires or just B and C fires.

• Will either be labeled DC (dry chemical), ABC, or BC.

Sodium Bicarbonate Extinguishers

• Are useful when faced with class B and C fires.• Preferred over dry chemical extinguishers

when a grease fire occurs. • May also prove useful in that some

extinguishers of this category protect cooking appliances when used.

Potassium Bicarbonate Extinguishers

• Are similar to sodium bicarbonate based extinguishers; yet, they may be able to put out fires of a larger size.

• Are typically filled with urea-based potassium bicarbonate or potassium chloride.

• Leave a heavy residue that can harm electrical equipment.

Foam Extinguishers

• When used these extinguishers coat the surface of a burning liquid with a chemical foam.

• Results in either the lowering of the temperature or the oxygen supply of the flame.

• The foams usually consist of water and thus cannot be used on electrical fires (class C fires).

Before Using a Fire Extinguisher…• Always perform these actions IMMEDIATELY

after a fire is discovered:1. If there is no personal risk involved, assist anyone

who is found to be in danger of personal harm.2. Call 911 and/or activate the fire alarm. This will notify

the fire department and the occupants of the building to the presence of a fire.

3. If the fire is small, one may use a fire extinguisher; however, one must know exactly what is burning as to allow for the use of the correct fire extinguisher.

a. If the wrong extinguisher is used it may make the problem worse, not better!

Let the Fire Department Handle it if…

• The fire is too big, as fire extinguishers are meant to be used when the fire first starts.

• Inadequate or inappropriate equipment are the only option (class B extinguisher for a class C fire).

• There is a danger of inhaling toxic smokes.• If your instincts tell you to.

Special Notes for Fire Extinguisher Use

• When using a fire extinguisher, always ensure that a safe, fire-free exit is to your back. This is important for if the fire cannot be contained, you may need to leave the room.

• Once an extinguisher is used, report the use to EH&S to ensure that it is inspected and refilled for future use.

References

• “Fire Extinguisher Training.” Clemson University Fire Department. Clemson University. Web March 30, 2013.

• “Fire Extinguisher Training.” Environmental Health and Safety Department. Oklahoma State University. Web March 30, 2013.

• “Occupational Safety and Health Standards: Portable Fire Extinguishers.” Occupational Safety and Health Administration. United States Department of Labor. Web March 30, 2013.

• Schreiber, Loren B., Lab Library, Unit Operations Laboratory, Department of Chemical Engineering, FAMU-FSU College of Engineering, January 7, 2013.