Question

Why is carbon dioxide an excellent fire extinguisher? (3m)

Answer 1

fires require oxygen to maintain combustion, and carbon dioxide displaces the oxygen feeding the fire. The other thing is that it is clean, unlike chemical agents which can get into electrical systems and eventually cause corrosion. A standard dry chemical ABC extinguisher uses mono-ammonium phosphate, which can cause both mess and corrosion. The other advantage of CO2 extinguishers is that if used they hold their pressure to be used again. With dry chemical the powder residue often gunks up the extinguisher check stem and O-ring, and so it leaks pressure.