Halon is a fire suppressant agent found in both Fire Suppression Systems (Halon 1301) and Fire Extinguishers (Halon 1211). This is the most effective extinguishing agent available.Halon is a clean agent, which means it leaves no residue when used, so causes no damage to your property.return to top.alon is a fire suppressant agent found in both Fire Suppression Systems (Halon 1301) and Fire Extinguishers (Halon 1211). This is the most effective extinguishing agent available. Halon is a clean agent, which means it leaves no residue when used, so causes no damage to your property. return to top.