The U.S. Consumer Product Safety Commission, Environmental Protection Agency, and Food and Drug Administration banned chlorofluorocarbons in aerosol sprays because these chemicals are harmful to Earth’s protective ozone layer. This step increased the willingness of other nations to discuss the ozone problem productively and on a continuing basis.

The furor over CFCs and ozone had a great impact on Western society; some responses had almost immediate results, whereas others may take decades to interpret and quantify. Even before the CFC ban, public opinion—in the form of consumer choice—had led to an estimated 38 to 41 percent drop in the yearly release of aerosol between 1973 and 1977. Many hailed this as a positive consequence of the public discussion of the subject. Consumer Product Safety Commission
Environmental Protection Agency;chlorofluorocarbons
Food and Drug Administration
Chlorofluorocarbons;U.S. ban

CFC use in the United States, however, represented only about 15 percent of the total world use. To make the ban truly effective, the rest of the CFC-producing and CFC-using nations would need to cooperate as well. Canada, Denmark, and Sweden soon enacted similar legislation, in part as a result of meetings organized by the United Nations Environment Program United Nations Environment Program and the EPA that brought together scientists and statesmen from the major CFC-producing nations of the world. It was considered encouraging that the various nations were willing to discuss the problem productively and on a continuing basis. The drafting of the Montreal Protocol Montreal Protocol in 1987 and its subsequent amendments in 1990 and 1992 eventually called for the discontinuation of production of CFCs. Additional revisions of the treaty were undertaken in later years as international scrutiny of the issue continued. Stabilization or reversal of ozone depletion was realized, causing many to hail the Montreal Protocol as the most successful international environmental agreement ever promulgated.

Another consequence of the diminution of CFC aerosol use was the worldwide search for new chemicals to be used in their place, with simultaneous examination of potential ozone-depleting effects. Many possible replacements were found to exist, including pump dispensers that require only air to form aerosols, simple hydrocarbons, dry powders, and other halogenated chemicals related to CFCs but lacking or containing low amounts of chlorine. All have advantages and disadvantages. Many chemical CFC substitutes were found to share the ability to deplete the ozone layer. Study of halons—close cousins of the CFCs used in firefighting foams—showed that they, too, are ozone depleters.

One of the dilemmas associated with finding replacements for CFCs is that nothing can be definitely identified as “ozone-friendly” without a testing period of a decade or longer. At the same time, the chemicals to be tested must be proven to be safe for consumers. That requirement limits their chemical composition to substances that are neither toxic nor flammable, and while flammability is easily tested, toxicity testing requires considerable time. However, progress in halting ozone depletion suggests for now that many of these concerns were overemphasized, and that optimism for improvement is justified. Chlorofluorocarbons;U.S. ban
Ozone layer;chlorofluorocarbons ban

• Benedick, Richard Elliot. Ozone Diplomacy: New Directions in Safeguarding the Planet. Rev. ed. Cambridge, Mass.: Harvard University Press, 1998. The definitive book about the Montreal Protocol. The author was the chief U.S. negotiator of the 1987 treaty.
• Bernards, Neil, ed. The Environmental Crisis: Opposing Viewpoints. San Diego, Calif.: Greenhaven Press, 1991. Provocative collection of essays on environmental topics from widely differing viewpoints. Contains several discussions of the CFC-ozone problem. Equally important are the thoughtful commentaries on the roles of the government, the public, and the activist in the solution of such problems.
• Hillary, Sir Edmund. Ecology 2000. New York: Beaufort Books, 1984. Contains useful information on the stratospheric ozone problem and on CFCs. Also examines other problems that may arise from ozone depleters or their removal from the atmosphere.
• Panofsky, Hans A. “The Earth’s Endangered Ozone.” Environment 120 (April, 1978): 16-20, 40. Good, objective overview. Discusses in detail but in simple terms the ozone layer, its perpetuation, and its destruction by human-made chemicals, such as chlorofluorocarbons.
• Parson, Edward A. Protecting the Ozone Layer: Science and Strategy. New York: Oxford University Press, 2003. A highly detailed history of international efforts to protect the ozone layer since the 1970’s.
• Roan, Sharon L. Ozone Crisis: The Fifteen-Year Evolution of a Sudden Global Emergency. New York: John Wiley & Sons, 1989. In-depth history of the CFC-ozone problem. Includes information on the chemistry of ozone and related materials and discusses potential consequences, solutions, and alternatives to the use of CFCs.
• Snyder, Carl H. The Extraordinary Chemistry of Ordinary Things. 4th ed. Hoboken, N.J.: John Wiley & Sons, 2003. Chemistry text for the nonscientist that covers the basic chemistry needed to evaluate the problems associated with CFC effects on ozone. Includes a useful section on the topic.

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Clean Air Act Is Revised

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United Nations Creates a Panel to Study Climate Change

U.N. Agreement Protects Ozone Layer

U.S. Congress Approves More Clean Air Act Amendments