Definition

Wet Chemical Fire Extinguisher

A wet chemical fire extinguisher is specifically designed for Class F fires involving burning cooking oils and fats. It discharges a fine mist of alkaline potassium solution that reacts with hot oil through saponification — forming a cooling, vapour-suppressing foam — and preventing dangerous re-ignition. Identified by a yellow label panel, it must be serviced annually under BS 5306-3.