It works very similar to halon; -bromine from the molecule scavenges the chemical reaction (i.e., the fire) by stripping hydrogen from the fuel source, creating hydrogen bromide (HBr), which interrupts the combustion cycle by reacting with combustion radicals to create water. The bromine is then free to start the process again. This chain breaking scavenging along with its physical properties that cool the fire results in extinguishing the fire very quickly.