What Does
Class D Fire Mean?
A Class D fire involves combustible metals, such as magnesium, titanium, sodium, potassium, lithium, and aluminum. In the context of Occupational Health and Safety (OHS), Class D fires are particularly hazardous because these metals can burn at extremely high temperatures and react violently with water or other common extinguishing agents, leading to explosions or the release of toxic fumes.
Other types of fires include Class A, Class B, and Class C.
Characteristics of Class D Fires
- Combustible Metals: The fire originates from metals that are combustible when finely divided (e.g., in powder or shavings form).
- High Temperature: These metals can ignite at high temperatures and often burn with intense heat.
- Reactivity: Combustible metals in a Class D fire may react with water or other substances, exacerbating the fire or causing secondary hazards.
Safeopedia Explains Class D Fire
Extinguishing Class D Fires
Most class D fires occur when the combustible metals are in dust, flake, shaving forms or molten. A class D fire cannot be extinguished by water as it produces hydrogen at high temperatures and eventually an explosion occurs and spreads of fire further. It is, therefore, a special extinguishing powder based in sodium chloride (edible salt) or other salts, are used to extinguish a class D fire. Sands are also effective in putting out a class D fire.
Class D Fires in the Workplace
Workers in industries where combustible metals are used must be trained in recognizing Class D fire risks and using appropriate firefighting equipment.
Materials that could cause a Class D fire should be stored and handled with care, following strict safety protocols to minimize the risk of ignition.
Workplaces should have clear procedures in place for dealing with Class D fires, including the use of suitable extinguishers and evacuation plans.
Class D fires are most common in industries such as manufacturing, metalworking, and laboratories, where combustible metals are frequently handled. Proper precautions, training, and the use of the right extinguishing agents are essential to manage the risks associated with these types of fires.