What is a fire? A fire is uncontrolled burning that damages the environment or property and endangers the life and health of people and other living things. It involves physical and chemical processes and takes place outside a dedicated hearth and without human control.
The factors that start a fire are oxygen, temperature (heat) and combustible material.
Fire brings a number of dangers to human life and health:
a) open flames and sparks, which injure people and endanger life;
b) toxic substances, which cause poisoning;
c) smoke, which severely reduces visibility;
d) a sharp rise in temperature (150 °C and above); a rising ambient temperature can burn the skin, eyes and airways to varying degrees.
– The permissible skin temperature does not exceed 45 °C.
e) lower oxygen concentration in the air;
f) the breakup and collapse of building structures.
Fires and flames are divided into classes.
The fire classes are:
- Class A – burning wood, paper, fabric, plastic, timber and similar materials;
- Class B – burning flammable and combustible liquids and meltable solids;
- Class C – burning flammable gases, such as methane, propane and others;
- Class D – burning magnesium, potassium, sodium and others;
- Class E – burning live electrical installations and equipment.
