How are fire extinguishers designated?

Each of the substances we are surrounded by incinerates in a specific way. Some materials burn out quickly, converting into ash, others melt down, emit flammable compounds, or glow. Considering various types of fire, people have developed different extinguishing agents and, most of all, properly adapted extinguishers. How to interpret the letter marks on fire extinguishers? Here is a couple of useful tips.

Published: 5-12-2022

What are extinguisher designations used for?

If we take a look at the inscriptions on a container with an extinguishing agent, we will see characteristic pictograms and large letters. Among other things, they indicate the type of extinguishing agent; for example, the CO2 extinguisher bears the symbol: GS, and the dry powder extinguisher; GP. The knowledge of these marks saved the life and property of many people! So where should we look for guidelines on the use of a particular model of extinguisher?

It is the standard letter marks on them that let us know their intended use. The marks indicate whether the extinguishers are designed for extinguishing a fire of solids, gaseous substances or liquids. When choosing the appropriate extinguisher, it is very helpful to take a look at the simple, universal graphics that accompany the letters and are understandable even for foreigners who are not fluent in Polish.

Symbols on extinguishers: what does the law say?

We should remember that extinguisher designations are not an invention of manufacturers or marketers. Specific information on the duty to apply particular symbols can be found in such legal acts as:

  • The Fire Protection Act of 24 August 1991,
  • Regulation of the Minister of Interior and Administration of 7 June 2010,
  • Polish Standards (including PN-EN 3-7+A1:2008 “Portable fire extinguishers”).

A compendium of currently applicable fire protection symbols is also available on the website of the National Headquarters of the State Fire Service. There we will learn that there are 5 basic types of extinguishers: A, B, C, D and F. How should we understand the letter marks? Here is a prompt.

Extinguishers marked “A”

Extinguishers marked “A” are intended for extinguishing fires of organic solids. Which materials do we refer to? Examples include:

  • wooden furniture,
  • books and other paper items,
  • natural fabrics (linen, cotton),
  • straw bales.

A specific feature of organic materials is that they produce coal when incinerated.

What is the meaning of a “B” pictogram  on an extinguisher?

What does the letter B mean on a fire extinguisher? Fire group B covers fusible materials and flammable liquids. Therefore, the extinguishers marked “B” will be helpful in extinguishing such substances as petrol, fuel oil, plastics, synthetic fibres, lacquers, or alcohols at concentrations exceeding 50% (ethanol, methanol). The letter “B” is usually accompanied by a symbol presenting a tilted, burning canister.

Extinguishers marked “C”, “D” and “F”: applications

In industrial conditions, production plants or specialised workshops, we will often see extinguishing agents marked “C”. What does this letter mean? It indicates that the device is designed for extinguishing fires of volatile substances. These are usually gases such as methane, propane, natural gas, hydrogen, etc.

The fire protection market also offers extinguishers marked “F” or “D”. The “D” models were developed to extinguish burning metals. The “F” extinguishers are used to eliminate fire caused by overheated food oils and fats which are used in households and restaurants.

Multifunctional ABC and BCE extinguishers

Manufacturers from the fire protection sector search for versatile solutions that will enable us to put down fires of different types using a single extinguishing agent. The effect of that search is the extinguisher marked “ABC”, which is used to extinguish fires from groups: A, B and C, that is solids, flammable liquids, and gases.

Another innovative product that is an alternative to the B and C extinguishers are the BCE extinguishers. How should we understand the BCE mark on an extinguisher?  Such devices are used for A and B fires, so when we have to deal with glowing electric equipment under voltage.

  1. K. Łangowski Gaśnice w zak³adach pracy (1) „Bezpieczeñstwo Pracy” 11(434)2007

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