Which Fire Extinguisher Should You Use?

There are a variety of extinguishers that use different extinguishing agents depending on the type of fire. Would you know which type to use if a fire broke out?

Water- Air Pressurized Water Extinguishers (APW) – These extinguishers use water as the main extinguishing agent, usually filled two thirds of the way with water. The other third is pressurized air. APW’s are ideal for Class A fires and extinguish the fire by “cooling the surface of the fuel to remove the heat element of the fire triangle.” According to OSHA, class A fires involve wood, paper, cloth, rubber, and certain plastics. FPT’s extinguisher manager, Rob Babcock, says an easy way to remember a Class A type fire is “Anything that is burnable that leaves an ash.”

CO2 or Dry Chemical – Carbon Dioxide Extinguishers – These extinguishers use CO2 as the main extinguishing agent. The non-flammable gas is under extreme pressure, allowing it to cool the fire because pieces of dry ice shoot from the horn. The CO2 works to displace the oxygen. According to OSHA, CO2 extinguishers are designed for Class B and C (flammable liquid and electrical) fires.

Multi Purpose- Dry Chemical Extinguisher – These extinguishers use ammonium phosphate to put the fire out by coating the fuel with a “layer of fire retardant powder, separating the fuel from the oxygen.” These are used for class A, B, and C fires.

Class K – Wet Chemical Extinguishers for Kitchen Fires – A class K fire extinguisher is designed to be used in the case of a kitchen fire. According to OSHA,

“Due to the higher heating rates of vegetable oils in commercial cooking appliances NFPA 10, Portable Fire Extinguishers, now includes a Class K rating for kitchen fires extinguishers which are now required to be installed in all applicable restaurant kitchens. Once a fire starts in a deep fryer, it cannot always be extinguished by traditional range hoods or Class B extinguishers.”

Class K extinguishers usually use potassium bicarbonate as an extinguishing agent. Furthermore, some Class K extinguishers spray a fine mist and are considered a Class K wet chemical extinguisher.

Clean Agent/Halocarbon Based Extinguisher – These extinguishers are ideal for a computer room/IT room where no residue or water can be used. A Halotron 1 extinguisher “is a clean agent that leaves no residue after application, and consequently inflicts little to no collateral damage on equipment in the vicinity of the fire.”

Class D Fire Extinguishers- These extinguishers are used for combustible metal fires. “Badger’s Class D Dry Powder Fire Extinguisher is ideal for addressing combustible metal fires involving metals like magnesium, sodium, potassium and sodium-potassium alloys.”

Of course, many buildings require a variety of different types of fire extinguishers to satisfy the many emergency scenarios that could arise.

For questions about what type of extinguisher would best fit your needs or to schedule a fire extinguisher training class, contact us or reach out to rob@fireprotectiontesting.com.

Wondering if your building is up to code? Contact FPT for a free compliance audit.

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