This report presents the findings of a select international committee of experts from industry and acedemia on the subject of chemical substitutes for fully halogenated chlorofluorocarbons (CFCs). This committee, over the course of two meetings, reviewed and discussed data and information on chemical alternatives for fully halogenated CFCs now in use. Also, committee members prepared brief reports highlighting specific areas of concern. FC-134a was identified as having the greatest current potential for replacing CFC-12; similarly, CFC-123 could replace CFC-11. The committee acknowledged that, while there are many other possible chemical replacements, there is a dearth of information on these compounds with regard to property data, toxicity, and performance in end-use applications. Investigation of new chemicals to serve as backup candidate substitutes if FC-134a and CFC-123 fall short of expectations was strongly recommended. Such investigations should include a preliminary screening of chemical, physical, and thermodynamic properties; acute toxicity; and likely atmospheric fate. Finally, several new chemicals were suggested for examination.