Safety Tips

Know your extinguisher

With so many types of Fire Extinguishers to choose from, selecting the proper one for your home, office or business can be an overwhelming task. Everyone should have at least one fire extinguisher at home or workplace, but it's just as important to ensure you have the proper type of fire extinguisher.

Fire extinguishers are divided into four categories, based on the different types of fires. The following is a quick guide to help choose the right type of extinguisher.

• Class Aextinguishers are for ordinary combustible materials such as paper, wood, cardboard, and most plastics. The numerical rating on these types of extinguishers indicates the amount of water it holds and the amount of fire it can extinguish.
• Class Bfires involve flammable or combustible liquids such as gasoline, kerosene, grease and oil. The numerical rating for class B extinguishers indicates the approximate number of square feet of fire it can extinguish.
• Class Cfires involve electrical equipment, such as appliances, wiring, circuit breakers and outlets. Never use water to extinguish class C fires - the risk of electrical shock is far too great!Class C extinguishers do not have a numerical rating. The C classification means the extinguishing agent is non-conductive.
• Class Dfire extinguishers are commonly found in a chemical laboratory. They are for fires that involve combustible metals, such as magnesium, titanium, potassium and sodium. These types of extinguishers also have no numerical rating, nor are they given a multi-purpose rating - they are designed for class D fires only.

• Some fires may involve a combination of these classifications. Your fire extinguishers should have ABC ratings on them. Here are the most common types of fire extinguishers:Water extinguishersor APW extinguishers (air-pressurized water) are suitable for Class A fires only. Never use a water extinguisher on grease fires, electrical fires or class D fires- the flames will spread and make the fire bigger! Water extinguishers are filled with water and pressurized with oxygen. Again - water extinguishers can be very dangerous in the wrong type of situation. Only fight the fire if you're certain it contains ordinary combustible materials only.

• Dry chemicalextinguishers come in a variety of types and are suitable for a combination of class A, B and C fires. These are filled with Foamor Powderand pressurized with nitrogen.
  • BC- This is the regular type of dry chemical extinguisher. It is filled with sodium bicarbonate or potassium bicarbonate. The BC variety leaves a mildly corrosive residue which must be cleaned immediately to prevent any damage to materials.
  • ABC - This is the multipurpose dry chemical extinguisher. The ABC type is filled with monoammonium phosphate, a yellow powder that leaves a sticky residue that may be damaging to electrical appliances such as a computer. Dry chemical extinguishers have an advantage over CO2 extinguishers since they leave a non-flammable substance on the extinguished material, reducing the likelihood of re-ignition.

• Carbon Dioxide (CO²)extinguishersare used for class B and C fires. CO² extinguishers contain carbon dioxide, a non-flammable gas, and are highly pressurized. The pressure is so great that it is not uncommon for bits of dry ice to shoot out the nozzle. They don't work very well on class A fires because they may not be able to displace enough oxygen to put the fire out, causing it to re-ignite. CO² extinguishers have an advantage over dry chemical extinguishers since they don't leave a harmful residue - a good choice for an electrical fire on a computer or other favourite electronic device such as a stereo or TV.

Always base your selection on the classification and the extinguisher's compatibility with the items you wish to protect.