Fires are classified by the fuel type that is burning. By the same approach, not all fire forms can be extinguished. According to the European Standard Classification of Fires, there are five fire groups in the UK. They can be studied more deeply with a Fire Risk Assessment Gloucester based company Keloscape provides.
Class A: ordinary flammable fires
Class A fires contain materials that have heated up to their ignition point, such as paper, wood or rubber. These are the most prevalent type of fire and are the simplest to extinguish. This form of fire can be put out by a water or foam fire extinguisher.
Class B: liquids that are flammable
Petrol, alcohol and solvents are classified as flammable liquids and contain liquids with an ignition temperature lower than 100 C. A low flashpoint also has flammable liquids. The flashpoint is the minimum temperature at which a liquid gives off enough flammable vapour to ignite, according to the Health and Safety Executive. Class B fires spread and emit black smoke. To put out the flames, a foam fire extinguisher is necessary.
Class C: Flammable Gases
Flammable gases, which include butane, petroleum and propane, have the ability to cause an explosion as one of the most dangerous forms of fire. For this purpose, the handling of gases in sealed containers is important. For tackling class C fires, a dry powder extinguisher is used.
Class D: Flames of Metal
Metals need high temperatures to ignite; but if water or foam is used to try to extinguish the flames, it can be especially dangerous once a fire gets going. Therefore, Class D fires are put out using a powder fire extinguisher type D.
Class F: oil fires for cooking
When heated to elevated temperatures, cooking oils and fats can cause fires. Water does not help to extinguish Class F fires, contrary to common opinion; a special wet chemical extinguisher is needed instead.