What is the danger of trying to extinguish a Class D fire with a Class A extinguisher?

When dealing with a Class D fire, which involves combustible metals like magnesium, titanium, or sodium, using a Class A extinguisher is highly inappropriate and potentially very dangerous. Class A extinguishers are designed for fires involving ordinary combustibles such as wood, paper, or fabric and use water or foam as extinguishing agents.

In the case of a Class D fire, applying water from a Class A extinguisher could lead to explosive reactions. When water comes into contact with burning metals, it can react violently, leading to the release of flammable hydrogen gas and causing the fire to spread or intensify. This reaction can create flying molten metal particles and explosive steam, posing a serious risk to anyone nearby.

Understanding the specific properties of different types of fires and their respective extinguishing agents is crucial in effectively managing fire hazards and ensuring safety.