Purchasing a fire extinguisher isn’t as straightforward as you think, it isn’t a case of buying any old unit and then leaving it handy in the event of a fire. There are different types of fire extinguishers and they all have separate uses, so before investing in a unit make sure you’re investing in the correct tool for your job.
Classes of Fire
Each class of fire corresponds to its own type of fire extinguisher, so here are the classes of fire:
Class A. Ordinary Combustibles – fires that involves woods, paper, fabrics and similar items. Class A fires create ash.
Class B. Flammable liquids – fires fuelled by gasoline, oil, grease, paints and other flammable liquids. Think of it like this: Class B fires involve fuels that bubble and boil.
Class C. Electrical equipment – this can be a fire started from conductors, wiring or any other electrical source. Class C fires involve electrical currents.
Class D. Combustible metals – these are the least common types of fires, ones that originate from metals like potassium, aluminum, magnesium and sodium. This fire extinguisher would generally be found in a laboratory.
Class K. Cooking materials – grease, animal fats, cooking oils (especially deep fat fryers). Class K fires involve kitchen components.
Types of Extinguishers
Extinguishers should be kept in a visible area and easily accessible, now the types of extinguishers:
APW (Air Pressurised Water) Extinguisher – the APW is designed for use on Class A fires only. It would be ineffective on any other class of fire and could lead to injury, and further spread of the fire.
Carbon Dioxide Extinguisher – designed for use on Class B, Class K and Class C fires only, it will smother fires started be electrics and flammable liquids. Ideal for laboratories, kitchens and areas where highly flammable liquids are found.
Dry Chemical Extinguisher – this will take out Class A, Class B and Class C fires, too. It expels a fine powder that coats the fire with a thin layer of dust, this is what smothers it – removing the oxygen from it. Another one you will find in mechanical rooms, offices, laboratories and chemical storage areas.
Wet Chemical Extinguisher – designed for Class K fires, specifically deep fat fryers.
Dry Powder Extinguisher – while this is similar to the dry chemical extinguisher it works by separating the fuel and the oxygen to kill the fire. They are used for both Class D and Class B.
Training and Maintenance
Once you have purchased the correct units your journey does not end there. You now need to ensure that employees are trained in how to use them. So, not only does each employee need to understand how to operate the extinguisher, but they need to understand what each different type is used for. In most cases you will have more than one type in an area, as many potential combustibles are within the zone. Using the wrong fire extinguisher could have dire consequences. Each new employee should also be trained upon their start with the company, and the training should be updated regularly to ensure that employees are prepared to deal with an emergency.
“You may find that your potential fire risks can be extinguished using just one type of fire extinguisher, perhaps if you are in an office and only at risk of fires in Class A, B, and C then you can rely on the Dry Chemical option.”
Fire extinguishers will also require regular maintenance (that includes monthly inspections, as well as recharging, plus an annual checkup) and records should be kept to reflect your compliance with the regulations that cover the maintenance of fire extinguishers. The monthly inspections can be completed by a responsible employee within your business, however the annual testing and service should be conducted by a trained professional from a fire protection company to ensure full compliance.
