Chapter 7 review questions

When using a portable fire extinguisher, how can you determine the best way to use it?

After selecting the appropriate size and type of extinguisher, perform a quick visual inspection for external condition, hose/nozzle in place, weight is heavy (empty extinguisher is light), pressure gauge is in operable range. When operating use PASS: P - pull the pin breaking the thin wire or plastic seal A - Aim the nozzle at the base of the fire S - Squeeze the handles together to release the agent S - Sweep the nozzle back and forth to cover the burning material pg. 355

How do Carbon Dioxide, dry chemical, and dry powder extinguishers differ?

Dry chemical agents are used for Class A, B , and C fires. Dry powder agents are used on class D fires. CO2 is best on Class B and C fires and is primarily a gas agent.

How are the ratings used for portable fire extinguishers determined?

They are determined by performance capability. Example: Class A rated from 1-A to 40-A - determines how much of the agent is in it and the range/duration Class B rated from 1-B to 640-B - rating based oin approximate square footage area of a flammable liquid of fire.

How are the classifications for portable fire extinguishers divided?

by the fire type they are designed to extinguish Class A - common combustible materials (wood, plastic, etc) Class B - Flammable liquids Class C- electronics or electrical fire Class D - combustible metals Class K - Kitchen fires from oils or fats

What are the basic procedures for the care and maintenance of portable fire extinguishers?

For maintenance, thoroughly inspect and disassemble the fire extinguisher. For inspection follow the rules: Serviceability, Accessibility, Simplicity of operation Make sure it's in proper location, inspect nozzle for obstruction, see if labels are legible, determine if the extinguisher is full.

How should you choose a portable fire extinguisher?

Select the appropriate extinguisher for the type of fire (fuel burning). Choose the extinguisher that minimizes risk to life and property and is effective in extinguishing the classified fire.

What types of procedures are used to inspect portable fire extinguishers?

Serviceability, Accessibility, Simplicity of Operation. more on pg.357

What are the differences between wet chemical stored-pressure, aqueous film forming foam (AFFF). and clean agent extinguishers?

CO2 extinguishers are most effective against Class B and C fires. Because the discharge is in the form of a gas, they have limited reach and the gas can be dispersed by wind. Does not require freeze protection. Wet chemical stored-pressure extinguishers are best used on Class K fires. They use a special potassium-based, low -pH agent formulated to operate on the principles of saponification. AFFF extinguishers are intended for class B fires. Mixed with water to produce a foam solution, different from Wet chemical stored-pressure extinguishghers. Also uses an air-aspirating foam nozzle producing a better quality foam.