Essentials of Fire Fighting, 5th Edition Chapter 6 — Portable Fire Extinguishers Firefighter I

Chapter 6 Lesson Goal After completing this lesson, the student shall be able to operate portable fire extinguishers effectively and safely following the policies and procedures set forth by the authority having jurisdiction. Firefighter I

Specific Objectives 1. Describe methods by which agents extinguish fire. 2. List mechanisms by which portable extinguishers expel their contents. 3. Distinguish among classifications of fires and the most common agents used to extinguish them. (Continued) Firefighter I

Specific Objectives 4. Describe types of extinguishers and their common uses. 5. Discuss extinguishers and agents for metal fires. 6. Explain the portable extinguisher rating system. (Continued) Firefighter I

Specific Objectives 7. Describe factors to consider in selecting the proper fire extinguisher. 8. Describe items to check for immediately before using a portable fire extinguisher. 9. Describe the PASS method of application. (Continued) Firefighter I

Specific Objectives 10. Summarize procedures that should be part of every fire extinguisher inspection. 11. Discuss damaged portable fire extinguishers and obsolete portable fire extinguishers. (Continued) Firefighter I

Specific Objectives 12. Operate a stored pressure water extinguisher. 13. Operate a dry chemical (ABC) extinguisher. (Skill Sheet 6-I-2) 14. Operate a carbon dioxide (CO2) extinguisher. (Skill Sheet 6-I-3) Firefighter I

Fire Extinguishment Methods Smothering Cooling Chain breaking Saponification Firefighter I

Portable Extinguisher Expulsion Mechanisms Manual pump Stored pressure Pressure cartridge Firefighter I

Fire Classifications Class A fires — Involve ordinary combustibles Easily extinguished with water, water-based agents (foam), dry chemicals Water most common agent used by fire service (Continued) Firefighter I

Fire Classifications Class B fires — Involve flammable/ combustible liquids, gases, greases Special fire hazards; should not be extinguished until fuel gas shut off Special-hazard fires get larger as fuel volume increases Extinguishing agents include carbon dioxide, dry chemical, Class B foam (Continued) Firefighter I

Fire Classifications Class C fires — Involve Class A or B fires created by electrical energy Do not use water, water-based agents until electrical energy eliminated Recommended method is to turn off or disconnect electrical power before using appropriate extinguisher (Continued) Firefighter I

Fire Classifications Class D fires — Involve combustible metals, alloys Can be identified by bright white emissions from combustion process Class D, dry powder extinguishers work best (Continued) Firefighter I

Fire Classifications Class K fires — Involve combustible cooking oils Examples are vegetable fats that burn at extremely high temperatures Most fuels found in commercial kitchens; can also be found in private homes Wet chemicals used in extinguishing systems Firefighter I

Pump-Type Water Extinguishers Intended for use on small Class A fires only All operate in similar manner Equipped with single- or double-acting pump Firefighter I

Stored-Pressure Water Extinguishers Air-pressurized water extinguishers or pressurized water extinguishers Useful for all types of small Class A fires (Continued) Firefighter I

Stored-Pressure Water Extinguishers Often used for extinguishing hot spots Operation Water stored in tank w/air or nitrogen Gauge shows pressurization Pressure forces water up tube, out hose Class A foam concentrate sometimes added Firefighter I

Water-Mist Stored-Pressure Extinguishers Use deionized water as agent, nozzles produce fine spray instead of stream Deionized water makes safe for use on energized electrical equipment Fine spray enhances cooling/soaking characteristics, reduces scattering of burning material Firefighter I

Wet Chemical Stored-Pressure Extinguishers Specifically designed to control/extinguish Class K fires in deep fryers Contain special potassium-based low-pH agent to cool/suppress fires in unsaturated cooking oils Courtesy of Ansul Corp. Firefighter I

Aqueous Film Forming Foam (AFFF) Extinguishers Suitable for Class A, Class B fires Fires/vapors from small liquid fuel spills Different from stored-pressure water extinguishers Tank contains specified amount of AFFF concentrate mixed with water Air-aspirating nozzle aerates solution (Continued) Firefighter I

Aqueous Film Forming Foam (AFFF) Extinguishers Water/AFFF solution expelled by compressed air or nitrogen To prevent disturbance of foam blanket, do not apply directly onto fuel; allow to rain onto surface/deflect off object (Continued) Firefighter I

Aqueous Film Forming Foam (AFFF) Extinguishers When AFFF/water mixed, finished foam floats on fuels lighter than water Vapor seal created by film of water extinguishes flame, prevents reignition (Continued) Firefighter I

Aqueous Film Forming Foam (AFFF) Extinguishers Foam has good wetting, penetrating properties on Class A fuels; ineffective on polar solvents Not suitable for fires in Class C, D fuels Most effective on static pools of flammable liquids Firefighter I

Clean Agent Extinguishers Designed as replacement for Halon 1211, use “clean agents” that discharge as rapidly evaporating liquids that leaves no residue Cool/smother fires in Class A, B fuels Nonconductive so can be used on Class C Approved by U.S. EPA Firefighter I

Carbon Dioxide (CO2) Extinguishers Found as both handheld/wheeled units Most effective in Class B, C fires Have limited reach; gas can be dispersed by wind Courtesy of Badger Fire Protection (Continued) Firefighter I

Carbon Dioxide (CO2) Extinguishers Carbon dioxide stored under its own pressure as liquefied gas ready for release at any time Wheeled units similar to handheld except wheeled are considerably larger Firefighter I

Dry Chemical Extinguishers For Class A-B-C fires and/or Class B-C fires; dry powder used on Class D only Commonly used today (Continued) Courtesy of Ansul Corp. Firefighter I

Dry Chemical Extinguishers Two basic types Regular B:C-rated Multipurpose and A:B:C-rated Commonly used dry chemicals Handheld units Wheeled units Firefighter I

Controlling/Extinguishing Metal Fires Special extinguishing agents, application techniques developed to control/extinguish metal fires No single agent controls/extinguishes fires in all combustible metals (Continued) Firefighter I

Controlling/Extinguishing Metal Fires Some powdered agents applied with portable extinguishers, others with shovel or scoop Appropriate application technique described in manufacturer’s technical sales literature (Continued) Firefighter I

Controlling/Extinguishing Metal Fires Portable extinguishers for Class D come in both handheld, wheeled units Regardless of applicator, powder must be applied in sufficient depth to completely cover burning area to create smothering blanket (Continued) Firefighter I

Controlling/Extinguishing Metal Fires Operation If small amount of burning metal on combustible surface, fire should be covered with powder 1 to 2 inch (25 to 50 mm) layer spread nearby, burning metal shoveled onto layer After extinguishment, material left undisturbed until cooled Firefighter I

Portable Extinguisher Rating System Portable extinguishers classified according to types of fire they extinguish Class A, B also rated according to performance capability System based on tests by UL, ULC Firefighter I

Classifications Class A — From 1-A through 40-A Class B — From 1-B through 640-B Class C — No tests Class D — Test fires vary Class K — Recognized by UL, ULC since 1996 Firefighter I

Multiple Markings Extinguishers for more than one class of fire identified by combinations of A, B, and/or C or symbols for each class Most common are A-B-C, A-B, B-C All must be labeled appropriately Unlisted units should not be used Ratings for each class are independent Firefighter I

Identification — Two Ways Geometric shapes of specific colors with class letter shown within shape NFPA® 10 recommended — Uses pictographs to make selection easier; shows types of fires on which extinguishers should not be used Firefighter I

Extinguisher Selection Factors Classification of burning fuel Rating of extinguisher Hazards to be protected Size/intensity of fire (Continued) Firefighter I

Extinguisher Selection Factors Atmospheric conditions Availability of trained personnel Ease of handling extinguisher Life hazard/operational concerns Firefighter I

Extinguisher Selection Considerations Select those that minimize risk to life/ property and are effective in extinguishing the fire type Dry chemical extinguishers should not be selected for use in areas where highly sensitive computer equipment is located Firefighter I

Extinguisher Check Immediately before use External condition Hose/nozzle Weight Pressure gauge After selecting size/type for situation, approach fire from windward side Firefighter I

Fire Extinguisher Operation All modern extinguishers operate in similar manner Pick up extinguisher by handles, carry to point of application (Continued) Firefighter I

Fire Extinguisher Operation Once in position, use PASS method P — Pull the pin A — Aim the nozzle S — Squeeze handles together S — Sweep nozzle back and forth (Continued) Firefighter I

Fire Extinguisher Operation Be sure agent reaches fire Apply agent from point where stream reaches but does not disturb fuel After fire knocked down, move closer to achieve final extinguishment (Continued) Firefighter I

Fire Extinguisher Operation If extinguishment not achieved after entire extinguisher discharged, withdraw/reassess If fire is in solid fuel reduced to smoldering phase, may be overhauled using appropriate tool (Continued) Firefighter I

Fire Extinguisher Operation If fire in liquid fuel, it may be necessary to apply foam through hoseline or simultaneously attack with more than one extinguisher If more than one extinguisher used simultaneously, work in unison and maintain constant awareness Firefighter I

Fire Extinguisher Inspections NFPA® 10 and most fire codes require portable extinguishers inspected at least once/year Verify that extinguishers Are in designated locations Not tampered with or activated No obvious damage/other condition (Continued) Firefighter I

Fire Extinguisher Inspections Servicing responsibility of property owner/building occupant Firefighters should include inspections in building inspection program (Continued) Firefighter I

Fire Extinguisher Inspections Three factors determine value Serviceability Accessibility Simplicity of operation NFPA® 10 describes procedures for hydrostatic testing of cylinders Firefighter I

Parts of Fire Extinguisher Inspections Ensure extinguisher in proper location/accessible Inspect discharge nozzle Inspect extinguisher shell Check for legible operating instructions on nameplate INACCESSIBLE (Continued) Firefighter I

Parts of Fire Extinguisher Inspections Check locking pin, tamper seal Determine whether full of agent, fully pressurized Check for date of previous inspection Examine condition of hose/fittings If any items deficient, remove from service Firefighter I

Damaged Fire Extinguishers Can fail at any time; could result in serious injury Leaking, corroded, otherwise damaged shells/cylinders should be discarded or returned to manufacturer for repair (Continued) Firefighter I

Damaged Fire Extinguishers Only slight damage/corrosion and uncertain whether safe — Should be hydrostatically tested If allowed by SOP, leaking hoses, gaskets, nozzles, and loose labels can be replaced by firefighters Firefighter I

Obsolete Portable Fire Extinguishers American manufacturers stopped making inverting-type extinguishers Manufacturing of extinguishers made of copper or brass with cylinders soft soldered or riveted together discontinued (Continued) Firefighter I

Obsolete Portable Fire Extinguishers Extinguishers using carbon tetrachloride and chlorobromomethane prohibited in workplace If obsolete extinguishers are discovered and occupant requests, firefighters should follow SOP to dispose of them Firefighter I

Halon Fire Extinguishers Included in Montreal Protocol U.S. stopped producing halogens at end of 1993 Units may still be in service Firefighter I

Summary In many cases, fire extinguishers can control or extinguish small fires in less time than it takes to deploy a hoseline. (Continued) Firefighter I

Summary Even though portable fire extinguishers may be found in many of the homes, apartments, and businesses that must be entered to extinguish fire, firefighters should only rely on those carried on the fire apparatus. (Continued) Firefighter I

Summary To use fire extinguishers safely and effectively, firefighters must know capabilities and limitations of the extinguisher — and their own capabilities and limitations — as well as the proper techniques for their application. Firefighter I

Review Questions 1. What are the five classes of fire and what do they involve? 2. What fires are aqueous film forming foam (AFFF) extinguishers most effective on? 3. How do carbon dioxide (CO2) portable extinguishers work? (Continued) Firefighter I

Review Questions 4. What are the three most common combinations for extinguishers with multiple markings? 5. List three factors that affect the selection of the proper portable fire extinguisher. (Continued) Firefighter I

Review Questions 6. What should be checked immediately before using a portable extinguisher? 7. What is the PASS method of application? 8. What procedures should be part of every fire extinguisher inspection? Firefighter I