CIESIN Thematic Guides

Chlorofluorocarbon Phaseout

Following the discovery of the ozone hole over Antarctica in the mid-1980s, chlorofluorocarbons (CFCs) were implicated as the primary agent responsible for ozone depletion. This has led to movements calling for reduction and eventual elimination of ozone-depleting substances. International agreements, such as the Montreal Protocol on Substances That Deplete the Ozone Layer, and national policy decisions have led industry and the scientific community to collaborate to find and develop safe alternatives to CFCs. Recent updates to the Protocol are outlined by Rowlands (1993) in "The Fourth Meeting of the Parties to the Montreal Protocol."

Many factors need to be considered in the phaseout process and in selecting alternative substances. Replacements are evaluated on criteria such as toxicity, chemical stability, ozone depletion potential, global warming potential, and suitability for performing the task of the substance they are replacing. Manzer (1990) offers an overview of the issues involved in alternative development in "The CFC-Ozone Issue." Hydrofluorocarbon-134a (HFC-134a) and hydrochlorofluorocarbon-141b (HCFC-141b) are two proposed alternatives to CFC-11 and CFC-12 in several applications. The uses of these and other alternative substances, as well as replacement procedures for CFCs, are discussed in the Chemical and Engineering News (C&EN) article "Looming Ban on Production of CFCs" (Zurer 1993).

"Essential uses" are another issue in phaseout discussions. Devices that do not have approved alternative substances or that would not be economically feasible if they were to undergo full-scale replacement may be granted exemptions to phaseout provisions drawn by the Environmental Protection Agency (EPA) and the Montreal Protocol. Metered-dose inhalers are one of the devices expected to receive exemption from the CFC ban. The C&EN article "CFC Users Seek Exemptions from Ban on Ozone-Depleting Substances" surveys possible exemptions (Zurer 1993).

Economic considerations are also a major factor in determining time frames for phaseouts. Immediate replacement of CFCs may be prohibitively expensive for certain applications, resulting in requests for longer phaseout times for the industries involved. Another factor complicating the transition issue is that replacement substances such as hydrochlorofluorocarbons (HCFCs) are themselves under phaseout schedules. These compounds are slated to be banned early in the next century, which would result in additional replacement costs for devices using HCFCs. The C&EN article "Industry, Consumers Prepare for Compliance with Pending CFC Ban" addresses these issues (Zurer 1992).

The Montreal Protocol Technology and Assessment Panel reviews technological and economic factors involved in the replacement of controlled substances by existing alternative compounds in the chapter "Economics" of the Montreal Protocol on Substances That Deplete the Ozone Layer, 1991 Assessment (United Nations Environment Programme 1991). Among the panel's conclusions are that sufficient technology and alternative substances exist to warrant the accelerated phaseout schedules defined by the Protocol amendments. In addition, the panel concludes that the long-term economic interests of all countries, including developing nations, are served by following the time schedules set forth by the Protocol.