Halogenated fire extinguishing agents, such as halon, were widely used as a fire-extinguishing medium onboard ships and in other enclosed spaces because of their ability to extinguish fires quickly and effectively. However, halon and other halogenated fire extinguishing agents were found to have a significant impact on the ozone layer and were therefore phased out under the Montreal Protocol, an international agreement to protect the ozone layer by phasing out the production and consumption of ozone-depleting substances.
Halons are highly effective fire suppressants, but they are also powerful greenhouse gases. These halons have a global warming potential thousands of times greater than carbon dioxide. When released into the atmosphere, they deplete the ozone layer and contribute to climate change. In addition, halons also have a very high atmospheric lifetime which means they will remain in the atmosphere for a long time.
As a result, halon and other halogenated fire extinguishing agents were phased out under the Montreal Protocol and were replaced by other fire-extinguishing agents that are less harmful to the environment, such as CO2.
It's worth noting that the phase-out of halons is an ongoing process, and some uses of halons may still be allowed in certain situations where no suitable alternatives are available, under the Montreal Protocol requirements.
