Chapter 7 Extinguisher Flashcards
NFPA 10
Standard for portable fire extinguishers
Class A
Water, water based, dry chem or class A foam Ordinary combustibles - wood paper plastic textiles etc
Class B
Flammable and combustible liquids and gases Extinguish with CO2, dry chemical and class B foam
Class C
Energized electrical equipment
Can’t use water or water based.
Use class C extinguishing agents
Class D
Combustible metals
Mag used in wheels and transmission components and some metal box springs for beds
Bright white fires.
Don’t use water - dry powder good but dry chemical is different than dry powder (dry powder can use potassium or sodium which will react violently)
Class K
Cooking oils such as vegetable or animal fats that burn at extremely high temp.
Wet chemical systems and portable fire extinguishers
Saponification
Alkaline based chemicals and certain cooking oils come into contact resulting in formation of a soapy film
Methods used to extinguish
Smothering Cooling Chain breaking Saponification If fuels have their own oxidizing agents (magnesium) oxygen depleting methods don’t work
Water extinguishing methods
Cooling
O2 depletion
CO2 extinguishing methods
O2 depletion
Cooling
Foam extinguishing methods
O2 depletion
Vapour suppression
Clean agent extinguishing methods
Chain inhibition
Cooling
Dry chem extinguishing methods
Chain inhibition
O2 depletion
Wet chem extinguishing methods
O2 depletion
Vapour suppression
Dry powder extinguishing methods
O2 depletion
Heat transfer cooling
