Tuletõrjevahendid

Tuletõrjevahendid, commonly translated as fire extinguishing agents, are substances or devices used to put out fires. Their primary function is to interrupt the chemical reaction of combustion by removing one or more of the essential elements required for fire: fuel, heat, oxygen, or the chain reaction. Various types of tuletõrjevahendid exist, each suited for different classes of fire.

Water is one of the most common and versatile agents. It works by cooling the fuel below its ignition temperature and also by producing steam, which smothers the fire by displacing oxygen. Water is effective against Class A fires, which involve ordinary combustible materials like wood, paper, and cloth.

Foam is another important agent, particularly effective against flammable liquid fires (Class B). Foam is created by mixing water with a foaming agent. When applied to burning liquids, the foam forms a blanket that separates the fuel from the oxygen, suppresses vapors, and cools the surface.

Dry chemical powders are versatile and widely used. These agents interrupt the chemical chain reaction of combustion. Different types of dry chemicals are available for various fire classes. For instance, ABC dry chemical extinguishers can handle Class A, B, and C (electrical) fires. BC dry chemical extinguishers are for flammable liquid and electrical fires.

Carbon dioxide (CO2) is a gaseous agent that extinguishes fires by displacing oxygen and by cooling. It is non-conductive and leaves no residue, making it ideal for protecting sensitive electrical equipment and delicate machinery (Class C and B fires). Halogenated agents, often referred to as halons, were historically used for their effectiveness in interrupting the chain reaction and for their low conductivity. However, due to environmental concerns regarding ozone depletion, their use has been largely phased out and replaced by cleaner alternatives.

Specialized agents exist for specific situations, such as wet chemical extinguishers for Class K fires (cooking oils and fats) and dry powder agents for Class D fires (combustible metals). The selection of the appropriate tuletõrjevahend depends on the type of fire, the materials involved, and the environment.