Which type of extinguisher should be used for a class C fire that involves gases?

For a class C fire, which involves flammable gases, the use of a dry powder extinguisher is the most effective and suitable option. Dry powder extinguishers are specifically designed to combat fires involving gases such as propane or natural gas. They work by smothering the flames and interrupting the chemical reaction that sustains the fire.

Unlike foam extinguishers, which are more effective on flammable liquid fires (class B) due to their ability to form a barrier over the liquid, or water extinguishers, which are not suitable for class C fires because water can conduct electricity and could pose a risk of electrocution or further spreading the fire, dry powder extinguishers can safely be applied to gaseous fires.

Wet chemical extinguishers, primarily designed for use on cooking oils and fats (class K fires), are also not appropriate for class C situations. Their formulation may not effectively extinguish a gas fire and could create additional hazards.

Thus, the correct choice emphasizes the need to select the right extinguisher type based on the specific fire classification, ensuring both safety and effectiveness in extinguishing the fire.