Chlorofluorocarbons

Chlorofluorocarbons (CFCs) are a class of man-made chemicals known by such tradenames as "Freon," "Genetron," and "Isotron." CFCs have been used in a wide variety of manufacturing steps and products including as a solvent in the electronics industry, foaming or blowing agent, aerosol propellant, fire extinguisher agent, dry cleaning solvent, degreasing agent, a key component in making rigid foam insulation for houses and household appliances, and foam packaging insulation material (known by the trade name of "Styrofoam"). Use of CFCs has declined as concern over their interaction with the environment has grown.

Inhalation of high concentrations affects the nervous and respiratory system. Initial symptoms include a reduced ability to concentrate, dizziness, headaches, and bronchial constriction, which may lead to sudden death. Intentionally inhaling CFCs from aerosol cans has resulted in the deaths of several teenagers.

Chlorofluorocarbons are highly volatile compounds, contributing to air pollution. CFCs are unusual because they do not break down when vaporized into the atmosphere. Instead, they rise slowly through the atmosphere, taking six to eight years to reach the stratosphere (the highest layer of the earth's atmosphere). Here CFCs can reside for more than 100 years. If global CFC production was stopped today, we would still experience the effects for over one hundred years.

Chlorofluorocarbons are implicated in two major threats to the global environment: the greenhouse effect and the reduction of the ozone layer. CFCs contribute to the greenhouse effect, warming the atmosphere by trapping heat which is then radiated back into the atmosphere. CFCs are more than 10,000 times as effective at trapping this radiated heat than carbon dioxide.

CFCs have also been shown to contribute to the depletion of the protective ozone layer in the atmosphere. In 1984 the ozone hole formed in Antarctica was larger than the United States and taller than Mount Everest. Ozone levels are depleted most dramatically in the Antarctic, but are being reduced around the world. As the chlorofluorocarbons break down, they release a chlorine atom which is capable of destroying tens of thousands of ozone molecules before being washed out of the atmosphere. Depletion of the ozone layer permits greater amounts of ultraviolet radiation to reach the earth. The increase in ultraviolet radiation affects human health by increasing the likelihood of developing skin cancer and cataracts and may depress the human immune system. Increased ultraviolet radiation reduces crop yields, depletes marine fisheries, damages construction materials, and increases smog. Between 1969and 1986, the average global concentration of ozone in the stratosphere had fallen about 2%.

World-wide recognition of the global threat from CFCs has begun. In 1977, the EPA and FDA banned the use of CFCs in the production of most aerosol cans in the United States. However, these chemicals need to be reduced on a global scale. In 1987, thirty-five countries signed the Montreal Protocol on Substances that Deplete the Ozone Layer. Provisions of the agreement include a freeze on CFC production at 1986 levels by 1989, a 20% reduction by 1993, and a 50% reduction of 1986 levels by 1998. However, governments which signed the Protocol need to enforce compliance and nations that did not sign it must agree to reduce CFC production for these measures to be effective.

Countries that signed the 1987 Montreal Protocol:

This is a global problem which we all can help solve at home. As consumers, we can influence industrial and government decision-makers with our dollars and votes. Do not use aerosol products. Avoid purchasing products wrapped in foam packaging material (In 1989, McDonalds has been involved in a campaign to recycle styrofoam containers of all kinds. You may wish to check with your local McDonalds to see if they are willing to -accept styrofoam containers.) Check your air conditioning (in home and car) and refrigeration systems for leaks and have them sealed. When having the air conditioning system of your car recharged, patronize service stations -which clean and recycle used coolant, rather than vaporizing it into the atmosphere. Use materials other than rigid foam insulation (blown in with CFC-1 1 or CFC-1 2) to insulate your home. Support legislation for reducing the amount of OFOs produced and for compliance with the Montreal Protocol.

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