Portable Fire Extinguishers Chapter 8 Portable Fire Extinguishers

Introduction Portable fire extinguishers designed to fight: Small fires Unusual fires Fires that cannot be reached quickly with hoselines Fire extinguishers are valuable tools. Four basic PASS steps Fire extinguishers come in a variety of types and sizes.

Fire Classification and Risk Type of material burning defines class of fire. Classes of fire used to identify type of extinguishers and agents Pre-incident plan for fuel types and locations

Class A Involves ordinary combustibles Can be extinguished with: Water Water-based agents Foam Multipurpose dry chemicals Water usually the agent used

Class B Flammable and combustible liquids, gases, and greases Special hazards Common extinguishing agents: Carbon dioxide Regular and multipurpose dry chemical Foam

Class C Involves energized electrical equipment Water-based agents cannot be used. Turn off electrical power. Categorized with another class of extinguisher: BC or ABC Agents include: Carbon dioxide Regular and multipurpose dry chemicals

Class D Combustible metals and alloys Erratic behaviour Water and other agents can react violently No universal Class D extinguisher for all metals Class D agents called dry powders  Not to be confused with dry chemicals

Class K New classification as of 1998 Fires in combustible cooking fuels Agents usually wet chemicals Agents used in fixed systems

Class K equipment.

Types of Fire Extinguishers Factors for selecting an extinguisher: Type and amount of fuel Person using extinguisher Type of building construction and occupancy Type of equipment protected Main objective extinguishing the fire

Various types of fire extinguishers.

Types of Extinguishing Agents Water is the basic agent for Class A materials. Loaded stream extinguisher Water-based foam extinguishers Aqueous film-forming foam (AFFF) Film-forming fluoroprotein foam (FFFP) Better penetration for Class A materials Reduces surface tension of the water Carbon dioxide Inert gas stored under pressure as a liquid capable of being self-expelled Dry chemical agents Particles propelled by gaseous medium

Kinds of Extinguishers Many types: Small and handheld Large and require a wheeled cart Pump-type extinguishers Stored pressure extinguishers Cartridge-operated extinguishers

(A) (B) (C) (A) Older versions of fire extinguishers are labeled with colored geometrical shapes with letter designations. (B) Newer fire extinguishers are labeled with a picture label system. (C) Many fire extinguishers can be used to fight more than one type of fire.

Inner workings of a stored pressure water extinguisher.

Inner workings of a stored pressure dry chemical extinguisher.

Inner workings of a carbon dioxide extinguisher with a fixed nozzle.

Rating Systems for Portable Extinguishers Each class of fuel subjected to a separate type of extinguisher test for its class Conducted by independent testing agency Appropriate ratings and symbols Class A Class B Class C

Class C test for electrical conductivity of agent.

Limitations of Portable Extinguishers Exceeding capabilities Designed for specific purposes First-aid method for fire extinguishment Pick the larger size Wrong class extinguisher may not do the job.

Portable Extinguisher Operation PASS outlines four simple steps for extinguisher use P: Pull the pin A: Aim the nozzle S: Squeeze the handle S: Sweep the base of the fire

Care and Maintenance of Portable Extinguishers Simple inspections and careful storage prevent most problems Move unit from its bracket. Do hand test weight. Do visual check. Recharging water extinguisher a simple process performed by any firefighter

Re-servicing an Extinguisher (B) (A) Unscrew and remove the top. (B) Add the manufacturer’s recommendation of water. (C) Add foam, if required. 8.23

Re-servicing an Extinguisher (D) (E) (D) Replace the top. (E) Charge the extinguisher with the manufacturer’s recommendation of air. 8.24

Inspection Requirements Many fire extinguishers are obsolete. Inspection is usually a visual inspection. If something does not look right, it should be removed and replaced. Extinguishers returned to service should be examined prior to their placement on apparatus.

Lessons Learned Fire extinguishers can be used as: Initial response tools To fight fires in special situations Firefighters classify fires by their fuels. Four-step process for using an extinguisher: PASS