Ozone

The Australian Halon Management Strategy (AHMS)


What is the AHMS?

Australia is a signatory to the Montreal Protocol on Substances that Deplete the Ozone Layer. The Protocol is an international treaty that sets out a mandatory timetable for the phasing out of ozone depleting substances, including halon, and urges Parties to act to minimise damage to the ozone layer.

The Australian Halon Management Strategy (AHMS) meets our international obligations under the Protocol to provide a framework for the responsible management of Australia's halon stocks to 2030 and the ultimate elimination of their use. Development of the AHMS has been based on extensive consultation with industry, the community and Commonwealth, State and Territory Governments. It represents a commitment from all of these sectors to the total phase out of halon use in Australia.

What are halons?

Halons are fire fighting agents that were introduced into Australia in the early 1970s. They quickly replaced many previously accepted fire fighting products because of their superior fire fighting characteristics and ease of use.

The effects of halon on the ozone layer

The ozone layer occurs in the upper atmosphere (the stratosphere) 15-30 km above the surface of the earth, and protects life on earth by absorbing ultra-violet (UV) radiation from the sun. UV radiation is linked to skin cancer, genetic damage and reduced productivity in agricultural crops and the food chain.

Halons are fully halogenated chemicals that have relatively long lifetimes in the atmosphere. They are broken down in the stratosphere releasing reactive bromine that is extremely damaging to ozone. Reactions involving bromine are estimated to be responsible for 25 per cent of the chemical destruction of ozone over Antarctica and 50 per cent over the Arctic. The ozone depleting potential of halons is up to 10 times greater than that of chlorofluorocarbons (CFCs). As such, halons are a very aggressive ozone depleting chemical. One kilogram of halon 1211 can destroy 50 tonnes of ozone.

Halon alternatives

A wide variety of alternatives are now available for the majority of traditional halon uses, although individually, none of the current alternatives covers the broad spectrum of applications that halon did.

Halon alternatives include halocarbon gases, inert gases and water mist systems. There is increasing industry awareness that a more sophisticated approach to fire protection engineering techniques for the given situation is required to provide the most effective fire protection.