Question: what are the materials used in a fire extinguisher?
Answer: The active material may be a powder such as potassium bicarbonate (KHCO3), liquid water, an evaporating fluorocarbon or the propelling agent itself. The most effective and common fluorocarbon used until recently for this application had been bromochlorodifluoromethane (CF2ClBr), referred to as halon 1211.