In April 199 I the National Aeronautics and Space Administration (NASA) of the United States reported that its atmospheric monitoring satellites had detected severe ozone depletion over northern latitudes, and a winter ozone hole over the Arctic region. NASA concluded that global ozone is being depleted much faster than previously predicted. Action to reduce emissions of ozone-depleting substances should therefore be a top priority for governments, producers and users of ozone-depleting substances.Bromine is present in the halons controlled by the Montreal Protocol. The presence of bromine in the halon molecule enhances fire fighting effectiveness. Unfortunately, bromine radicals are also strong ozone-depleting agents. For the past 30 years, halons have been widely used in fire fighting equipment, and have been released into the atmosphere. Once there, CFCs and halons migrate to the layer of ozone that protects the Earth from the Sun’s harmful ultraviolet radiation and cause damage. The Montreal Protocol, signed in 1987, is the first agreement to protect the ozone layer. Signatories have agreed to phase out the production of halons in the developed countries by 1994.Users of halon fixed systems and portable halon fire extinguishers are reducing both the quantity of halons that they use and their halon emissions. Many users of portable halon fire extinguishers are adopting training techniques that minimize the release of halons. Manufacturers have improved the design of all types of halon fire extinguishing equipment and companies that service fire equipment have improved maintenance procedures; these efforts have reduced halon leaks and accidental emissions.Users are being encouraged to utilize non-halon fire protection alternatives that can provide an adequate level of fire protection. Recycled halon will be used to supply the needs of critical halon uses on civil aircraft, military vehicles, ships and aircraft, and other important installations.To ensure that sufficient quantities of halons are available after 1st January 1994, when halon production stops, national halon banks should be established. UNEP lE/PAC will act as an information clearing-house to help facilitate international transfers of recyclable halons between national halon banks.Research is being carried out into environmentally acceptable substances that have some of the same fire fighting characteristics as halons. Substances with some of the same properties as the existing halons will be available in the near future. However, replacement chemicals are expected to be considerably more-expensive than existing halons and it is unlikely that they could be used as recharge agents for existing halon equipmentUNEP lE/PAC, in cooperation with other international organizations, is acting as an information exchange centre on ozone-depleting substances, and is providing practical advice on all aspects of reducing halon use in fire extinguishing equipment.