Wet chemical extinguishing solutions are based on which chemical?

• A. Potassium carbonate based
• B. Sodium bicarbonate
• C. Ammonium phosphate
• D. Calcium hydroxide

Answer: (A)

Wet chemical extinguishing solutions are designed for cooking-oil fires (Class K) and rely on potassium-based chemistry to treat fats. The potassium ions saponify the fats, creating a soapy layer that cools, smothers, and seals the surface to prevent re-ignition. Among the options, the idea of a potassium-based formulation aligns with how these agents work, which is why potassium carbonate-based is the best match in this set. The other choices don’t fit because they involve different chemistries: sodium bicarbonate is a different dry-chemical family and doesn’t saponify fats effectively; ammonium phosphate is typical of other dry powders; calcium hydroxide isn’t used for cooking-oil fires and doesn’t provide the same fat-saponifying action.