Classification of fire extinguishers: types and useful information
Knowing the classification of fire extinguishers is functional to the correct choice of these instruments for the fire protection in the company.
The fires are not all the same: each has different characteristics, depending on the degree of participation of a combustible material to the flames. That's why having the extinguisher suitable for the fire resistance class is one of the most effective means of first aid.
Therefore, not only for companies subject to fire prevention control (DPR 151 of 2011) but also for all activities that want to guarantee the best safety conditions, it is necessary to pay particular attention to the choice of fire-fighting equipment, based on the working environment.
We see in detail the various types of fire extinguishers and their use.
Classification of fire extinguisher: types
In order to make the right choice between the different types of fire extinguishers, two important technical factors must be taken into consideration:
-Fire classes
-Extinguishing agent more suited to the nature of the fire.
As identified in the reference norm UNI EN 2:2005, the fire classes indicate the characteristic nature of the flames of a fire. Here are they:
-A: It affects all fires arising from solid materials such as paper, wood, leather, rubber, textiles, plastics, etc.;
-B: Fires generated by flammable liquids such as benzine, hydrocarbons, alcohol, solvents, mineral oils;
-C: All types of fire arising from gases such as methane, LPG, hydrogen, acetylene, butane and propane;
-D: Fires affecting the combustion of metals such as zinc, aluminium, magnesium, sodium, potassium, titanium, etc.;
-E: Fire originating from live electrical appliances (class not foreseen by the European classification but internationally recognised); The fire extinguisher is inserted by the inscription "Usable on live electrical appliances";
-F: Fires due to oils and fats of animal or vegetable origin used in cooking appliances, such as those in domestic areas.
Thanks to the information received from the fire classes you can understand what the appropriate extinguishing substance is. These fire extinguishers according to the individual extinguishing agents:
-Powder extinguisher: great efficacy of fire extinguishing by act of suffocation, cooling and chemical inhibition, mainly uses saline compounds such as potassium bicarbonate, ammonium sulphate and monoammonium phosphate. Suitable for class A, B, C, D fires;
-Water-based fire extinguishers, including those with foam: they act for cooling and suffocation of fire type A and B;
-CO2 fire extinguishers: Carbon dioxide content in liquid state, by pressurization it comes out in the gaseous state, creating an abrupt cooling (-79 °) and generating "dry ice" particles that act by suffocation and cooling of the fuel. Suitable for B and C burners.
Another aspect, not to be assumed, concerns the weight of the extinguisher: the models up to 20 kg are portable, while those beyond that capacity are trolley fire extinguishers (according to the norm UNI EN 3-7:2008) to facilitate their transport and use.
The weight also reflects the same amount of extinguishing inside the fire extinguisher, which determines the minimum operating time during its use.
To ensure the proper functioning of the extinguishers it is indispensable, after the purchase, to provide periodic maintenance according to the regulations in force.
Classification of fire extinguisher: how to read the label
Every fire extinguisher in the rule shows a label, generally colour contrasting with the background, divided into 5 parts to highlight different information:
In addition, all fire extinguishers must be accompanied by:
For example, if on the label we find 43 A 233 B C written:
How to use a fire extinguisher
Despite the different typologies may present some differences, in general a fire extinguisher is composed of:
-Tank: Container for extinguish and/or propellant;
-Valve: mechanism to regulate the flow of the extinguish;
-Hose: Flexible duct to direct the extinguishing flow (it may be absent in small fire extinguishers).
Here are some useful steps to follow to learn how to use a fire extinguisher:
1. Break the seal of assurance, turn the safety and remove it by pulling it outwardly;
2. Grasp the dispensing handle with one hand and with the other grip the tip of the nozzle to direct the jet;
3. Press the lever to operate the jet, directing it to the base of the fire and, if necessary, create a protective barrier from the flames, if required;
4. Distance yourself from the fire in such a way that the jet is effective and does not exceed the flames by disperding;
5. After making sure that the outbreak is completely switched off, store the fire extinguisher in place and leave the fire place.
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