When a fire breaks out on-premises, it is possible to fight it yourself using one of the fire extinguishers that may be located in your building. However, certain types of fire extinguishers can’t be used on certain fires; doing so would do more damage than good. This article will explain the classification system of fires, and which extinguishers can be used on which.
The European Standard Classification of Fires
The ESCF is a method of classifying fires that are recognised throughout the European Union. Under it, fires are separated into 5 different classes, with an additional classification for electrical fires. Specifically, these categories are:
- Class A: These are ordinary combustible fires and the most common kind. They occur whenever material like wood or paper reach their burning point. The fire will burn until either the heat, oxygen or fuel that is burning are removed.
- Class B: Flammable liquids make up Class B fires. These fires start with liquids that have a burning point of less than 100 degrees celsius and typically will burn easily because of a low flashpoint. Examples of these liquids are things such as petrol, kerosene, or alcohol
- Class C: Flammable gases can cause explosions if ignited, even at very low concentrations of gas. Fuels like butane or propane fall under this category.
- Class D: Metal Fires are difficult, both in terms of starting and fighting. Metals conduct very efficiently, meaning very large quantities of heat are required to start a metal fire, but more often they are caused due to shavings being ignited. Certain metals, like potassium, burn violently when exposed to either water or air; this can mean they explode.
- Electrical Fires: Since electricity is the ‘ignition’ for electrical fires, they aren’t given their own classification under this system. However, they are still very dangerous, as pooling water from extinguishers can cause electrocution to whoever is fighting the fire. They can be caused by any faulty electrical system, including your TV or an industrial circuit board.
- Class F: Cooking oil fires constitute the last category. They feature very high temperatures and spread further if extinguished with water.
Types of Fire Extinguisher
As each type of fire has its own constitution, each has its own difficulties in fighting it. As such, different types of fire extinguishers have different contents so that you can use the correct one to fight whatever fire has appeared. The contents of the extinguisher will be marked on the label, as well as markings indicating which classification of fires it should be used against.
Explanations of each fire extinguisher follow:
- Water Extinguishers: Water-based fire extinguishers are given a Class A rating, meaning they can be safely used against fires on fuels like wood, paper, packaging etc. Water and oil do not mix, so using them on cooking fires will just spread the fire around, and they will not have an impact on metal fires outside of possibly causing explosions.
- AFFF Foam: This foam is designed to prevent the re-ignition of fires, and smoothers the fuel to starve it of oxygen. It can be used on Class A, Class B, and, in some cases, electrical fires. The individual extinguisher will list if the foam contained within has been tested for electrical fires.
- Carbon Dioxide: CO2 extinguishers have a Class B rating, given that liquid fires are what they were designed to counter. However, because CO2 is not a conductor, it is also possible to safely use them on Electrical Fires.
- ABC Powder: As the name implies, these extinguishers can be safely used on Class A, Class B, and Class C fires. Furthermore, they are also safe to use on electrical fires. A warning though, is that they have an inhalation risk, and so it is recommended that you don’t use them in homes or small rooms if there is a viable alternative for fighting the fire.
- Water Mist: These extinguishers spray a fine mist using a curtain-creating nozzle. They can therefore be used on all types of fires besides metal fires; despite being water-based, they are safe to use on electrical fires because the mist does not pool, and vapours do not conduct electricity.
- Wet Chemical: Wet Chemical extinguishers’ spray is specifically designed to deal with the high heat burning of cooking oil fires. However, they typically also all have an additional Class A rating. Specific brands can also be used on Class B fires, but you should check this on your extinguisher.
Using a Fire Extinguisher – Fire Extinguisher Pass System
Using a fire extinguisher is simple, and the technique can be memorised using the acronym PASS:
- P- Pull the pin
- A- aim the nozzle at the fire’s base. This smothers whatever is burning rather than just the flames.
- S- Squeeze the trigger, doing so in a controlled and collected manner.
- S- Sweep from side to side. Maintaining your aim at the base of the fire will ensure good coverage over the source of the fire until it is extinguished
Note that, ordinarily, an extinguisher will give out a continuous discharge for around 10-20 seconds before stopping. Never turn your back on it, even if you think it is extinguished; it’s entirely possible that there is a part still burning buried under something else.
Finally, even if you didn’t use all the contents of the extinguisher, you will have to get it recharged. The last thing you want is for another fire to break out and do not have an extinguisher ready to go.
All working premises should ensure that the right fire extinguisher is readily available for their staff. They should also invest in specialist training, particularly where non-standard extinguishers are required so that employees know how to use them when they have no other choice.
TutorCare Ltd offer Fire Extinguisher Practical training that covers everything from safety checks to a practical test. Purchased alongside the popular Fire Marshalling course, and Fire Safety Awareness training, TutorCare can tailor fire safety training to your needs offering the best possible training experience.
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