Fire extinguishers and their ratings explained
Although there are five different types of fire extinguishers – powder, foam, CO², water, and wet chemical – and six different classes of fire, for simplicity, in this post we’re going to focus on Class A fire types. Those ignited on solids, such as wood, paper, and plastic. Because these are the most commonly ignited fires and the most commonly required fire extinguishers.
Powder (blue label), foam (cream label), and water (red label) fire extinguishers are all suitable for use on Class A fires. With powder fire extinguishers being the most broadly used by all business types.
Each type of fire extinguisher is rated on its ability to extinguish fires. This is done through a series of tests. With Class A fires, this involves igniting a fire on a traditional wooden cot of a specific size. Each relevant fire extinguisher is tested to see how much of the cot fire it can snuff. The ratings are then listed on the side of each extinguisher. So, the standard 9 litre water fire extinguisher, for example, is rated 13A. Indicating that in the testing environment, it was able to extinguish 1.3m of the cot fire.
British Standard 5306 simplifies this with the guidance that a 13A rated fire extinguisher typically covers around 200 square metres of floor.
How many fire extinguishers do I need for my business?
So far, so confusing?
While it’s useful to know how fire extinguishers are rated, it doesn’t fully clarify how many your business needs. So, let’s break it down. But before we begin, it is really important to reiterate that the following information merely provides a loose guide. And only a professional fire risk assessment will be able to tell you the exact fire extinguisher needs for your business.
Right, so on we go!
Unless your premises is very small, with a floor area of below 100m2, it’s a good idea to follow the rule that you need at least two Class A fire type extinguishers per floor. More in large buildings.
Use our handy quick Class A fire extinguisher calculator to work out approximately how many basic fire extinguishers you need for your business. Simply enter in your approximate floor space and the calculator will give you a basic estimate on how many extinguishers you should have.