Fire Extinguishers

Fire Extinguisher Types

The Essentials of Fire Extinguishers

There are many types of fire extinguishers it is important to use the proper extinguisher for the job. It also needs to be noted that for a fire extinguisher to be effective the extinguisher must be:

  • the right type/rating for the job.
  • must be accessible and close at hand
  • must be in good working order
  • used on a fire that is still small
  • must be used by a trained person

A full outline of fire extinguishers can be found here: Health and Safety Ontario – Fire Extinguishers


Examples of Fire Extinguisher Types and Usage

  • Halotron extinguishers use a non-conducive “clean agent” chemical that is a rapidly evaporating non-conductive liquid that leaves no residue. It is effective against Class A, B and C fires in computer areas and clean rooms.
  • Regular dry chemical powder extinguishers are a more economical solution against both Class B and Class C fires. They are a free flowing, non-caking dry chemical that is non-conductive.
  • Copper (Cu) dry powder extinguishers operate by the same mechanisms as the NaCl extinguishers. These are generally superior to other extinguishers for Class D fires caused by Lithium.
  • Sodium chloride (NaCl) dry powder extinguishers can be used against Class D fires. They form a crust over top of the fire that prevents oxygen from reaching the blaze and dissipating heat away from any burning metals.
  • Wet chemical extinguishers are designed just for Class K fires. They are more efficient leaving no chemical residue to clean up in the aftermath.
  • AFFF extinguishers (Aqueous Film Forming Foam) are used for Class A and B fires,. They leave a sealing film over the flammable materials to prevent potential re-ignition of vapors. They are often used as a pre-emptive measure on flammable liquid spills to prevent ignition.
  • FFFP extinguishers (Film Forming Fluoroprotein) are designed for Class A and B fires. They fow more slowly than AFFF, leaving a heavier with smothering foam blanketing over a smaller area.
  • Carbon dioxide (CO2) extinguishers use non-contaminating and odorless gases commonly used in industrial settings. They smother Class B fires by eliminating oxygen and are non-conductive when used against Class C fires.
  • “Purple K” extinguishers, contain a specially fluidized potassium-based dry chemical which are particularly effective against Class B fires. They are electrically non-conductive.
  • Water mist extinguishers are designed for use against Class A fires where a Class C hazard exists. The nozzle creates a fine mist that protects the user against electrical shock while simultaneously soaking a larger area to prevent fire spread. They are available with a non-magnetic canister and bracket for safety especially in ‘clean’ rooms and MRI settings.

Fire Extinguisher Ratings

Fire Sprinkler Rating & Usage Guide

Classes of Fire Extinguishers

Class A Fire Extinguisher SymbolClass A Extinguishers

Class A Extinguishers work by cooling the area and will put out fires burning ordinary combustibles such as wood or paper and some plastics or textiles. These should not be used on liquid combustible fires because the fire may flare up or spread. The numerical rating indicates the equivalent cooling power of 1.25 US Gallons (4.73 liters) or water, eg. 3A would indicate a cooling power of 3.75 US Gallons (14.2 liters) of water.

Class B Fire Extinguisher SymbolClass B Extinguishers

Class B Extinguishers work by smothering the flames, i.e. cutting off the oxygen and should be used on fires involving flammable liquids, such as grease, gasoline, oil, etc. The numerical rating for this class of fire extinguisher indicates the approximate number of square feet of a flammable liquid fire that a professional can expect to extinguish. Class B extinguishers can be used in place of Class A but may require some water to ensure the fire is completely extinguished.

Class C Fire Extinguisher SymbolClass C Extinguishers

Class C Extinguishers are suitable for use on electrically energized equipment. This class of fire extinguishers does not have a numerical rating. Class C fires are essentially a Class A or Class B fire occurring on electrified equipment  An Example of this would be a 20B:C would be used on an machine-oil fire occurring on an electric CNC machine.  The presence of the letter “C” indicates that the extinguishing agent is non-conductive.

Class D Fire Extinguisher SymbolClass D Extinguishers

Class D Extinguishers are designed for use on flammable metals and are often specific for the type of metal in question. The relative effectiveness is detailed on the extinguisher nameplate for the specific combustible metal fire for which it is recommended. These extinguishers generally have no rating nor are they given a multi-purpose rating for use on other types of fires.


Class K Fire Extinguisher SymbolClass K Extinguishers

Class K fire extinguisher is used on fires involving cooking media (fats, grease, and oils) in commercial cooking sites such as restaurants. These fire extinguishers work on the principle of saponification i.e. the process of conversion of fat or oil into soap and alcohol by the action of heat in the presence of aqueous alkali. Saponification takes place when alkaline mixtures, such as potassium acetate, potassium citrate, or potassium carbonate, are applied to burning cooking oil or fat. The alkaline mixture combined with the fatty acid creates a soapy foam on the surface that holds in the vapors and steam and extinguishes the fire. These extinguishers are identified by the letter K.

Multi-Class Rated Fire Extinguishers

Many extinguishers available today can be used on different types of fires and will be labeled with more than one designation, e.g. A-B, B-C, or A-B-C.


Fire Extinguisher Installation & Inspection in Ontario

fire extinguishers ontario

Fire Extinguisher Installation

If you need fire extinguishers installed for your property or project, our certified specialist will install the correct class of extinguisher in the appropriate locations. Ensuring your compliance plays a significant role in the reduction of property and personnel loss due to fire.

We guarantee your Fire Extinguishers to be:  

  • Properly located and easily accessible
  • Designed for the specific hazards in your facility
  • Fully charged and ready for immediate use
  • Certified in compliance with national, provincial and local requirements

Fire Extinguisher Inspection

If you manage or own a property, portable fire extinguishers are your first line of defense.  Stevenson Sprinkler & Fire Protection will inspect and certify your fire extinguishers to insure your facility is in compliance with provincial standards.

Fire Extinguisher Inspection Frequency

Every 12 months all fire extinguishers are to be inspected per Ontario regulations. You will have certification tags on each extinguisher upon successful inspection.

NFPA 10 Standard for Portable Fire Extinguishers

Highlights of an Annual Inspection:

  • Proper Extinguisher for hazard
  • Proper mounting height and bracket
  • Unobstructed discharge hose
  • Proper agent weight and pressure
  • Proper distribution of extinguishers
  • Safety seals and tamper indicators in place
  • Ensure that extinguisher is properly identified and is unobstructed

No-Hassel Inspection Schedules

Never miss a due date. Count on us to keep track!

Once we certify your fire extinguishers you don’t ever have to worry about missing due dates. Every 12 months we call to schedule service and ensure you have fire extinguishers in good working order should an emergency arise.

Call Today for a Free Quote: (905) 562-7575


Serving the following areas: Oakville, Milton, Burlington, Hamilton, Ancaster, Guelph, Kitchener, Cambridge, Brantford, Caledonia, Grimsby, Lincoln, Jordan Station, St. Catharines, Niagara-on-the-Lake, Thorold, Smithville, Pelham, Welland, Port Colborne, Fort Erie, Hagersville, Jarvis, Nanticoke, Port Dover, Simcoe, Waterford, Ohsweken, Saint George, Ontario, Canada


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4520 Jordan Road, Suite 1

Jordan Station, ON L0R 1S0

(905)-562-7575 (Phone)
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