What are Chlorofluorocarbons and Halons?

Chlorofluorocarbons (CFCs) and halons are man-made chemicals that exist as gases or liquids. Chlorofluorocarbons contain chlorine, fluorine and carbon. Halons are similar but contain bromine or iodine. They are neither toxic nor flammable.

They were first manufactured in 1930 under the trademark Freon. Chlorofluorocarbons and halons have lifespans in the atmosphere of 60 to 110 years.


They do not occur naturally; they are always manufactured. They are currently used as coolants in industrial, home and automobile refrigeration and air conditioning, foaming agent and cleaning solvents. In the past they were commonly used as propellants in aerosol cans. Halons are used in special-purpose fire extinguishers and protection systems in such areas as computer rooms and electronic areas.

The chart below shows how chlorofluorocarbons were used in Canada in 1986.

Canada is responsible for less than three percent of global chlorofluorocarbon use; and of those used in Canada in 1986, Alberta used about 10 percent or 2000 tonnes.

The Effects

Chlorofluorocarbons have two major, different - and often confused - effects in the atmosphere.

1. Greenhouse effect: chlorofluorocarbons and halons act as greenhouse gases and are considered major contributors to the concerns discussed in the fact sheet Greenhouse Effect.

2. Ozone-depletion effect: chlorofluorocarbons and halons are not destroyed in the lower atmosphere but waft slowly upward toward the stratosphere where they finally break down. Each of the chlorine or bromine atoms released in that breakdown is capable of destroying tens of thousands of ozone (O3) molecules - thus contributing to the thinning of the protective ozone layer.

Even though chlorofluorocarbons and halon emissions are being stopped today, the destruction of the stratospheric ozone layer will still continue, because chlorofluorocarbons and halons already released will move slowly up to the stratosphere and destroy ozone for the next 60 to 100 years.

What Has Been Done So Far?

Internationally there is commitment to stop compounding the problem and to reduce the use of chlorofluorocarbons and other ozone-depleting substances. International discussions began in 1981 and led to the 1985 Vienna Convention which establishes monitoring and scientific assessment activities.

Most members of the international community (including Canada) agreed in 1987 to The Montreal Protocol on Substances that Deplete the Ozone Layer. It set a schedule for reducing use of chlorofluorocarbons and halons by 1999 to 50 percent of the levels used in 1986. At a meeting in Helsinki in 1989, participating nations agreed to accelerate that timetable to 85 percent reduction by 1999. More recently Canada announced that it was prepared to end their use by 1997 and urged other nations to agree to meet earlier targets.

Canada played a key role in the Vienna Convention and The Montreal Protocol, and is encouraging a national objective to completely eliminate ozone-depleting substances. Alberta supports the national objective and, in consultation withthe federal government, is developing regulations and plans for the recovery, recycling and destruction of these substances.

Substitutes already have been found for certain uses of chlorofluorocarbons. In 1980 Canada banned their use as propellants in consumer items such as hair sprays, deodorants and antiperspirants. Major producers of polystyrene insulation were to switch to a chlorofluorocarbon substitute by the end of 1989 and the world's largest manufacturer of chlorofluorocarbons is to phase out their manufacture by the year 2000. A major automobile manufacturer has announced that it will equip its auto dealers with chlorofluorocarbon recovery and recycling systems for servicing vehicle air conditioners. Market responses are proceeding so quickly that the reductions proposed by The Montreal Protocol will be exceeded.

Further Information

Air quality issues - greenhouse gases, acid deposition (acid rain) and smog - cannot be addressed in isolation. Their complex inter-relationships make achieving the goal of clean air for the futre a challenge for individuals, industry and governments alike. The Clean Air Strategy for Alberta is providing an opportunity for Albertans to participate in meeting that challenge.

To assist Albertans in participating in the Clean Air Strategy for Alberta, the Alberta government has prepared a series of fact sheets and a glossary. Their purpose is to help Albertans understand the magnitude of the environmental and economic considerations, the complexity of the science, the potential requirements for changes in lifestyle, and the challenges facing individuals, industry and government.

List of Fact Sheets

An Overview, Greenhouse Effect, Acid Deposition (Acid Rain), Ozone - Stratospheric and Ground-Level, Carbon Dioxide, Sulphur Oxides, Methane, Nitrogen Oxides, Volatile Organic Compounds, Chlorofluorocarbons and Halons, Energy Efficiency, Policy Instruments, Glossary, Renewable Energy

Other information on chlorofluorocarbons (CFCs) and halons:

(1) The Montreal Protocol on Substances that Deplete the Ozone Layer. Final Act. 1987.

Clean Air Strategic Alliance, 9th Floor, Sterling Place, 9940 - 106 Street, Edmonton, Alberta, Canada, T5K 2N2, ph. 403/427-9793, fx. 403/422-3127, em:

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